xfs: fix issues that cause userspace warnings

Some of the code shared with userspace causes compilation warnings
from things turned off in the kernel code, such as differences in
variable signedness. Fix those issues.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

diff --git a/fs/xfs/xfs_ialloc.c b/fs/xfs/xfs_ialloc.c
index bd4e2a7..266024b 100644
--- a/fs/xfs/xfs_ialloc.c
+++ b/fs/xfs/xfs_ialloc.c
@@ -1342,7 +1342,7 @@
 	xfs_agblock_t	cluster_agbno;	/* first block in inode cluster */
 	int		error;	/* error code */
 	int		offset;	/* index of inode in its buffer */
-	int		offset_agbno;	/* blks from chunk start to inode */
+	xfs_agblock_t	offset_agbno;	/* blks from chunk start to inode */
 
 	ASSERT(ino != NULLFSINO);