Attempt to clean up compiler warnings

as given in https://cirrus-ci.com/task/5117093567791104?command=main

src/dpchaos.c

@@ -423,7 +423,7 @@ void net_init_pf(struct dpchaos_s *dpchaos)
       dbprintln("Can't find EA for \"%s\"", npf.osnpf_ifnam);
       if (ife) {
 	dbprintln("Found interface '%s', ea %s", ife->ife_name,
-		  (ife->ife_ea != NULL && memcmp(ife->ife_ea,"\0\0\0\0\0\0", ETHER_ADDR_LEN) == 0) ? "found" : "not found");
+		  (memcmp(ife->ife_ea,"\0\0\0\0\0\0", ETHER_ADDR_LEN) == 0) ? "found" : "not found");
       } else
 	dbprintln("Can't find interface '%s'!", npf.osnpf_ifnam);
     } else {
@@ -1287,7 +1287,7 @@ pfbuild(void *arg, struct in_addr *ipa)
   // Check the ethernet type field
 #if KLH10_NET_PCAP
 #define MAX_PFLEN 136 // really need only 130
-  u_char bpfilter[MAX_PFLEN];
+  char bpfilter[MAX_PFLEN];
   char eastr[OSN_EASTRSIZ];
   // must also check for address since interface may be in promisc mode although we didn't ask for it
   sprintf(bpfilter,

src/dvch11.c

@@ -592,7 +592,7 @@ ch11_cmd_status(struct ch11 *ch, FILE *of)
   if (dpc->dpchaos_ifmeth_chudp)
     fprintf(of, " CHUDP port: %d.\n", ch->ch_chudp_port);
   else {
-    if (dpc->dpchaos_ifnam)
+    if (dpc->dpchaos_ifnam[0])
       fprintf(of, " Using ifc=\"%s\"", dpc->dpchaos_ifnam);
     fprintf(of, " ether addr %02X:%02X:%02X:%02X:%02X:%02X\n",
 	    dpc->dpchaos_eth[0],dpc->dpchaos_eth[1],dpc->dpchaos_eth[2],
@@ -627,12 +627,12 @@ ch11_cmd_status(struct ch11 *ch, FILE *of)
 	  (int)dp_xrcmd(dp_dpxfr(&ch->ch_dp)), (int)dp_xrcnt(dp_dpxfr(&ch->ch_dp)));
   fprintf(of,"Input buffer: ");
   if (ch->ch_iptr)
-    fprintf(of,"%d chars\n",ch->ch_iptr - ch->ch_rbuf);
+    fprintf(of,"%d chars\n", (int)(ch->ch_iptr - ch->ch_rbuf));
   else
     fprintf(of,"none\n");
   fprintf(of,"Output buffer: ");
   if (ch->ch_optr)
-    fprintf(of,"%d chars\n",ch->ch_optr - ch->ch_sbuf);
+    fprintf(of,"%d chars\n", (int)(ch->ch_optr - ch->ch_sbuf));
   else
     fprintf(of,"none\n");
   fprintf(of,"Receive count: %d\n", ch->ch_rcnt);  
@@ -815,7 +815,7 @@ ch11_read(struct device *d, register uint18 addr)
     chaos_start(ch);
 
   switch (addr) {
-/*  case UB_CHWBF:		/* Write buffer (write only) = CHMYN */
+/*  case UB_CHWBF:		/ * Write buffer (write only) = CHMYN */
 /*     break; */
   case UB_CHMYN:		/* My chaos address (read only) */
     val = ch->ch_myaddr;

src/dvlites.c

@@ -302,7 +302,7 @@ int lites_init (unsigned int prt)
   if (prt == 0)
     return lites_init_usb ();
 				/* enable access to the port */
-  if (ret = !ioperm (prt,PORT_MAX,ENABLE)) {
+  if ((ret = !ioperm (prt,PORT_MAX,ENABLE))) {
     port = prt;			/* access granted, note port */
     outb (0,port+PORT_CONTROL);	/* initialize the displays */
     for (i = 0; i <= UNIT_MAX; --i) {

src/inexts.c

@@ -261,7 +261,9 @@ insdef(i_extend)
 
 #elif KLH10_CPU_KS
 # if (IX_N == 040 || IX_N == 020)	/* Faster check if power of 2 */
-    if (LHGET(xw) & (((~(IX_N-1))<<9) | (AC_MASK<<5)))	/* Check op and AC fields */
+#  define IX_MASK ((~(unsigned int)(IX_N-1))<<9)
+    if (LHGET(xw) & (IX_MASK | (AC_MASK<<5)))	/* Check op and AC fields */
+#  undef IX_MASK
 # else
     if (xop >= IX_N || (LHGET(xw) & (AC_MASK<<5)))	/* Check op, AC field */
 # endif

src/kn10clk.c

@@ -1092,6 +1092,8 @@ clk_itusset(int32 usec)
 	case CLKENT_ST_MQUIET:
 	    ce->cke_oticks = clk_usec2tick(ce->cke_usec);
 	    break;
+	default:
+	    break;
 	}
     }
 

src/osdsup.c

@@ -913,7 +913,7 @@ os_rtmget(register osrtm_t *art)
 {
 #if HAVE_SETITIMER /* && HAVE_GETTIMEOFDAY ; implied */
     static osrtm_t os_last_rtm = {0,0};
-    if (!gettimeofday(art, (struct timezone *)NULL) == 0)
+    if (gettimeofday(art, (struct timezone *)NULL) != 0)
 	return FALSE;
 				/* did time go backwards? */
     if ((os_last_rtm.tv_sec > art->tv_sec) ||

src/vmtape.c

@@ -1804,6 +1804,9 @@ vmt_rspace(register struct vmtape *t,
 	    while (tpc_recfwd(t) > 0
 		&& !t->mt_eof && !t->mt_eot && --cnt) ;
 	break;
+    default:
+	/* Unexpected tape format value */
+	break;
     }
     t->mt_frames = origcnt - cnt;
     return TRUE;
@@ -3070,6 +3073,10 @@ vmt_rput(register struct vmtape *t,
 	    return FALSE;
 	}
 	break;
+
+    default:
+	/* Unexpected tape format value */
+	break;
     }
     return vmt_ioend(t);
 }
@@ -3099,6 +3106,9 @@ vmt_eput(register struct vmtape *t,
     case VMT_FMT_TPS:
 	/* Possible but not implemented yet */
 	break;
+    default:
+	/* Unexpected tape format value */
+	break;
     }
     return TRUE;
 }