[PATCH] fix return of compat_sys_sched_getaffinity

From: Anton Blanchard <anton@samba.org>

On success getaffinity should return the size of mask.  It looks like
Randy's patch (which fixed a bogus return) missed this bit.

In reality I'm not sure if we care, and with cpu bitmasks this stuff is
going to break.

kernel/compat.c

@@ -425,9 +425,11 @@ asmlinkage int compat_sys_sched_getaffinity(compat_pid_t pid, unsigned int len,
 				    &kernel_mask);
 	set_fs(old_fs);
 
-	if (ret > 0)
+	if (ret > 0) {
+		ret = sizeof(compat_ulong_t);
 		if (put_user(kernel_mask, user_mask_ptr))
 			return -EFAULT;
+	}
 
 	return ret;
 }