x86: simplify result processing of cpu_flags_match()

Make more obvious what the success and failure paths are, and in
particular that what used to be at the "skip" label can't be reached
by what used to be straight line code.

gas/ChangeLog

+2018-03-08  Jan Beulich  <jbeulich@suse.com>
+
+	* config/tc-i386.c (parse_insn): Move success return up. Combine
+	failure returns.
+
 2018-03-08  Jan Beulich  <jbeulich@suse.com>
 
 	* config/tc-i386.c (cpu_flags_match): Add GFNI check to AVX

gas/config/tc-i386.c

@@ -4487,34 +4487,26 @@ check_suffix:
     {
       supported |= cpu_flags_match (t);
       if (supported == CPU_FLAGS_PERFECT_MATCH)
-	goto skip;
-    }
+	{
+	  if (!cpu_arch_flags.bitfield.cpui386 && (flag_code != CODE_16BIT))
+	    as_warn (_("use .code16 to ensure correct addressing mode"));
 
-  if (!(supported & CPU_FLAGS_64BIT_MATCH))
-    {
-      as_bad (flag_code == CODE_64BIT
-	      ? _("`%s' is not supported in 64-bit mode")
-	      : _("`%s' is only supported in 64-bit mode"),
-	      current_templates->start->name);
-      return NULL;
-    }
-  if (supported != CPU_FLAGS_PERFECT_MATCH)
-    {
-      as_bad (_("`%s' is not supported on `%s%s'"),
-	      current_templates->start->name,
-	      cpu_arch_name ? cpu_arch_name : default_arch,
-	      cpu_sub_arch_name ? cpu_sub_arch_name : "");
-      return NULL;
+	  return l;
+	}
     }
 
-skip:
-  if (!cpu_arch_flags.bitfield.cpui386
-	   && (flag_code != CODE_16BIT))
-    {
-      as_warn (_("use .code16 to ensure correct addressing mode"));
-    }
+  if (!(supported & CPU_FLAGS_64BIT_MATCH))
+    as_bad (flag_code == CODE_64BIT
+	    ? _("`%s' is not supported in 64-bit mode")
+	    : _("`%s' is only supported in 64-bit mode"),
+	    current_templates->start->name);
+  else
+    as_bad (_("`%s' is not supported on `%s%s'"),
+	    current_templates->start->name,
+	    cpu_arch_name ? cpu_arch_name : default_arch,
+	    cpu_sub_arch_name ? cpu_sub_arch_name : "");
 
-  return l;
+  return NULL;
 }
 
 static char *