rescan_partitions(): make device capacity errors non-fatal

Herton Krzesinski reports that the error-checking changes in
04ebd4aee5 ("block/ioctl.c and
fs/partition/check.c: check value returned by add_partition") cause his
buggy USB camera to no longer mount.  "The camera is an Olympus X-840.
The original issue comes from the camera itself: its format program
creates a partition with an off by one error".

Buggy devices happen.  It is better for the kernel to warn and to proceed
with the mount.

Reported-by: Herton Ronaldo Krzesinski <herton@mandriva.com.br>
Cc: Abdel Benamrouche <draconux@gmail.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/partitions/check.c

@@ -499,9 +499,9 @@ int rescan_partitions(struct gendisk *disk, struct block_device *bdev)
 		if (!size)
 			continue;
 		if (from + size > get_capacity(disk)) {
-			printk(KERN_ERR " %s: p%d exceeds device capacity\n",
+			printk(KERN_WARNING
+				"%s: p%d exceeds device capacity\n",
 				disk->disk_name, p);
-			continue;
 		}
 		res = add_partition(disk, p, from, size, state->parts[p].flags);
 		if (res) {