PM / Hibernate: Drop the check of swap space size for compressed image

For compressed image, the space required is not known until
we finish compressing and writing all pages.
This patch drops the check, and if swap space is not enough
finally, system can still restore to normal after writing
swap fails for compressed images.
Signed-off-by: Barry Song <Baohua.Song@csr.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

kernel/power/swap.c

@@ -773,8 +773,7 @@ static int enough_swap(unsigned int nr_pages, unsigned int flags)
 
 	pr_debug("PM: Free swap pages: %u\n", free_swap);
 
-	required = PAGES_FOR_IO + ((flags & SF_NOCOMPRESS_MODE) ?
-		nr_pages : (nr_pages * LZO_CMP_PAGES) / LZO_UNC_PAGES + 1);
+	required = PAGES_FOR_IO + nr_pages;
 	return free_swap > required;
 }
 
@@ -802,10 +801,12 @@ int swsusp_write(unsigned int flags)
 		printk(KERN_ERR "PM: Cannot get swap writer\n");
 		return error;
 	}
-	if (!enough_swap(pages, flags)) {
-		printk(KERN_ERR "PM: Not enough free swap\n");
-		error = -ENOSPC;
-		goto out_finish;
+	if (flags & SF_NOCOMPRESS_MODE) {
+		if (!enough_swap(pages, flags)) {
+			printk(KERN_ERR "PM: Not enough free swap\n");
+			error = -ENOSPC;
+			goto out_finish;
+		}
 	}
 	memset(&snapshot, 0, sizeof(struct snapshot_handle));
 	error = snapshot_read_next(&snapshot);