fix typo

From-SVN: r24652

gcc/genextract.c

@@ -397,7 +397,7 @@ fancy_abort ()
 }
 
 char *
-xstrdup (s1)
+xstrdup (input)
   const char *input;
 {
   register size_t len = strlen (input) + 1;

gcc/genrecog.c

@@ -1624,7 +1624,7 @@ change_state (oldpos, newpos, indent)
 }
 
 char *
-xstrdup (s1)
+xstrdup (input)
   const char *input;
 {
   register size_t len = strlen (input) + 1;