io.c (gfc_match_inquire): Replace "-1" by a defined constant.

2015-01-26  Tobias Burnus  <burnus@net-b.de>

        * io.c (gfc_match_inquire): Replace "-1" by a defined constant.

From-SVN: r220135

gcc/fortran/ChangeLog

+2015-01-26  Tobias Burnus  <burnus@net-b.de>
+
+	* io.c (gfc_match_inquire): Replace "-1" by a defined constant.
+
 2015-01-26  Janus Weil  <janus@gcc.gnu.org>
 
 	PR fortran/64230

gcc/fortran/io.c

@@ -4000,7 +4000,7 @@ gfc_match_inquire (void)
 
   if (inquire->unit != NULL && inquire->unit->expr_type == EXPR_CONSTANT
       && inquire->unit->ts.type == BT_INTEGER
-      && mpz_get_si (inquire->unit->value.integer) == -1)
+      && mpz_get_si (inquire->unit->value.integer) == GFC_INTERNAL_UNIT)
     {
       gfc_error ("UNIT number in INQUIRE statement at %L can not be -1", &loc);
       goto cleanup;