[PATCH] compat_sys_nfsservctl(): handle errors correctly

Correct some error handling on the compat version of the nfsservctl()
system.  It was detecting errors while copying in the arguments from user
space, but then attempting to use the arguments anyway.  This didn't seem
so good.
Signed-off-by: NPeter Staubach <staubach@redhat.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: Neil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

fs/compat.c

@@ -2170,9 +2170,12 @@ asmlinkage long compat_sys_nfsservctl(int cmd, struct compat_nfsctl_arg __user *
 
 	default:
 		err = -EINVAL;
-		goto done;
+		break;
 	}
 
+	if (err)
+		goto done;
+
 	oldfs = get_fs();
 	set_fs(KERNEL_DS);
 	/* The __user pointer casts are valid because of the set_fs() */