MIPS: Prevent buffer overrun in uninitialised variable fix

gcc/
	* config/mips/mips.c (mips_expand_vec_perm_const): Re-fix
	uninitialized variable warning to avoid buffer overrun.

From-SVN: r247022

gcc/ChangeLog

+2017-04-20  Matthew Fortune  <matthew.fortune@imgtec.com>
+
+	* config/mips/mips.c (mips_expand_vec_perm_const): Re-fix
+	uninitialized variable warning to avoid buffer overrun.
+
 2017-04-20  Alexander Monakov  <amonakov@ispras.ru>
 
 	PR other/71250

gcc/config/mips/mips.c

@@ -21358,7 +21358,7 @@ mips_expand_vec_perm_const (rtx operands[4])
 
   /* This is overly conservative, but ensures we don't get an
      uninitialized warning on ORIG_PERM.  */
-  memset (&orig_perm[nelt], 0, MAX_VECT_LEN);
+  memset (orig_perm, 0, MAX_VECT_LEN);
   for (i = which = 0; i < nelt; ++i)
     {
       rtx e = XVECEXP (sel, 0, i);