xfs: fix data fork format filtering during inode repair

Coverity noticed that xrep_dinode_bad_metabt_fork never runs because
XFS_DINODE_FMT_META_BTREE is always filtered out in the mode selection
switch of xrep_dinode_check_dfork.

Metadata btrees are allowed only in the data forks of regular files, so
add this case explicitly.  I guess this got fubard during a refactoring
prior to 6.13 and I didn't notice until now. :/

Coverity-id: 1617714
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/inode_repair.c

@@ -1055,9 +1055,17 @@ xrep_dinode_check_dfork(
 			return true;
 		break;
 	case S_IFREG:
-		if (fmt == XFS_DINODE_FMT_LOCAL)
+		switch (fmt) {
+		case XFS_DINODE_FMT_LOCAL:
 			return true;
-		fallthrough;
+		case XFS_DINODE_FMT_EXTENTS:
+		case XFS_DINODE_FMT_BTREE:
+		case XFS_DINODE_FMT_META_BTREE:
+			break;
+		default:
+			return true;
+		}
+		break;
 	case S_IFLNK:
 	case S_IFDIR:
 		switch (fmt) {