jfs: replace hardcoded magic number with DTPAGEMAXSLOT constant

Replace hardcoded value 127 with DTPAGEMAXSLOT constant in boundary
checks within jfs_readdir() and dtReadFirst(). This improves code
maintainability and ensures consistency with the defined maximum
slot value.

Signed-off-by: Zheng Yu <zheng.yu@northwestern.edu>
Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>

Author: cla7aye15I4nd

fs/jfs/jfs_dtree.c

@@ -2903,7 +2903,7 @@ int jfs_readdir(struct file *file, struct dir_context *ctx)
 		stbl = DT_GETSTBL(p);
 
 		for (i = index; i < p->header.nextindex; i++) {
-			if (stbl[i] < 0 || stbl[i] > 127) {
+			if (stbl[i] < 0 || stbl[i] >= DTPAGEMAXSLOT) {
 				jfs_err("JFS: Invalid stbl[%d] = %d for inode %ld, block = %lld",
 					i, stbl[i], (long)ip->i_ino, (long long)bn);
 				free_page(dirent_buf);
@@ -3108,7 +3108,7 @@ static int dtReadFirst(struct inode *ip, struct btstack * btstack)
 		/* get the leftmost entry */
 		stbl = DT_GETSTBL(p);
 
-		if (stbl[0] < 0 || stbl[0] > 127) {
+		if (stbl[0] < 0 || stbl[0] >= DTPAGEMAXSLOT) {
 			DT_PUTPAGE(mp);
 			jfs_error(ip->i_sb, "stbl[0] out of bound\n");
 			return -EIO;