xfs: fix integer overflow in xrep_bmap

The variable declaration in this function predates the merge of the
nrext64 (aka 64-bit extent counters) feature, which means that the
variable declaration type is insufficient to avoid an integer overflow.
Fix that by redeclaring the variable to be xfs_extnum_t.

Coverity-id: 1630958
Fixes: 8f71bed ("xfs: repair inode fork block mapping data structures")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Carlos Maiolino <cem@kernel.org>

Author: Darrick J. Wong

fs/xfs/scrub/bmap_repair.c

@@ -801,7 +801,7 @@ xrep_bmap(
 {
 	struct xrep_bmap	*rb;
 	char			*descr;
-	unsigned int		max_bmbt_recs;
+	xfs_extnum_t		max_bmbt_recs;
 	bool			large_extcount;
 	int			error = 0;