wrong return type for sys_wait4

[Ted Unangst]

harmless, but wrong.

Index: kern_exit.c
===================================================================
RCS file: /home/tedu/cvs/src/sys/kern/kern_exit.c,v
retrieving revision 1.102
diff -u -p -r1.102 kern_exit.c
--- kern_exit.c 6 Jul 2011 21:41:37 -0000       1.102
+++ kern_exit.c 25 Jul 2011 19:29:46 -0000
@@ -432,7 +432,7 @@ reaper(void)
        }
 }
 
-pid_t
+int
 sys_wait4(struct proc *q, void *v, register_t *retval)
 {
        struct sys_wait4_args /* {