xfs_repair: fix off by one error when rebuilding high keys

Fix an off-by-one error when scanning a rmap btree block for high keys
as part of rebuilding rmap btrees during phase 5.  This causes
xfs_repair to emit a corrupt filesystem, which is bad.

This can be reproduced pretty easily by exporting
TEST_XFS_REPAIR_REBUILD=1 and running generic/051 with a 1k block size.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>

diff --git a/repair/phase5.c b/repair/phase5.c
index 85d1f4f..1bacfc7 100644
--- a/repair/phase5.c
+++ b/repair/phase5.c
@@ -1500,7 +1500,7 @@
 		bt_key->rm_offset = cpu_to_be64(
-		for (i = 1; i < numrecs - 1; i++) {
+		for (i = 1; i <= numrecs; i++) {
 			bt_key = XFS_RMAP_HIGH_KEY_ADDR(bt_hdr, i);
 			key.rm_startblock = be32_to_cpu(bt_key->rm_startblock);
 			key.rm_owner = be64_to_cpu(bt_key->rm_owner);