SCP: Fix remote console command table ordering to have STEP near the beginning

This allowed user entered S to match the SAMPLEOUT command instead
of STEP.  That then identified a bug in the intended socket output
processing to attempt to be written to the undefined debug file.

As discussed in #854

scp.c

@@ -13562,7 +13562,7 @@ int Fprintf (FILE *f, const char* fmt, ...)
 int ret = 0;
 va_list args;
 
-if (sim_mfile || (f == sim_deb)) {
+if (sim_mfile || (sim_deb && (f == sim_deb))) {
     char stackbuf[STACKBUFSIZE];
     int32 bufsize = sizeof(stackbuf);
     char *buf = stackbuf;