[PATCH] swsusp: print error message when swapping is disabled

This patch gives some clues to the user when swapping is not enabled during
swsusp.  Please apply.
Signed-off-by: Zhu Yi <yi.zhu@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

kernel/power/swsusp.c

@@ -847,8 +847,11 @@ asmlinkage int swsusp_save(void)
 {
 	int error = 0;
 
-	if ((error = swsusp_swap_check()))
+	if ((error = swsusp_swap_check())) {
+		printk(KERN_ERR "swsusp: FATAL: cannot find swap device, try "
+				"swapon -a!\n");
 		return error;
+	}
 	return suspend_prepare_image();
 }