dm io: write error bits form long not int

write_err is an unsigned long used with set_bit() so should not be passed
around as unsigned int.

http://bugzilla.kernel.org/show_bug.cgi?id=10271

Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/md/dm-io.c b/drivers/md/dm-io.c
index b8e342f..8f25f62 100644
--- a/drivers/md/dm-io.c
+++ b/drivers/md/dm-io.c
@@ -114,7 +114,7 @@
 			wake_up_process(io->sleeper);
 
 		else {
-			int r = io->error;
+			unsigned long r = io->error;
 			io_notify_fn fn = io->callback;
 			void *context = io->context;