two minor bug fixes for dfa.c

[Aharon Robbins]

Hi.

1. The setbit_wc() function for not MBS_SUPPORT has return type bool
   but does not return a value
2. A test for `defined MBS_SUPPORT' should just be `MBS_SUPPORT' since
   MBS_SUPPORT is now always defined.

Diff below.

Thanks,

Arnold
------------------------------
--- /usr/local/src/Gnu/grep/src/dfa.c   2011-11-22 23:32:58.501681998 +0200
+++ dfa.c       2011-11-27 21:09:35.195545161 +0200
@@ -585,7 +608,12 @@
 }
 #else
 # define setbit_c setbit
-static inline bool setbit_wc (wint_t wc, charclass c) { abort (); }
+static inline bool setbit_wc (wint_t wc, charclass c)
+{
+  abort ();
+  /*NOTREACHED*/
+  return false;
+}
 #endif
 
 /* Like setbit_c, but if case is folded, set both cases of a letter.  For
@@ -622,7 +650,7 @@
   static int utf8 = -1;
   if (utf8 == -1)
     {
-#if defined HAVE_LANGINFO_CODESET && defined MBS_SUPPORT
+#if defined HAVE_LANGINFO_CODESET && MBS_SUPPORT
       utf8 = (STREQ (nl_langinfo (CODESET), "UTF-8"));
 #else
       utf8 = 0;