jfs: avoid -Wtautological-constant-out-of-range-compare warning

jfs: avoid -Wtautological-constant-out-of-range-compare warning

A recent change for the range check started triggering a clang warning:

fs/jfs/jfs_dtree.c:2906:31: error: result of comparison of constant 128 with expression of type 's8' (aka 'signed char') is always false [-Werror,-Wtautological-constant-out-of-range-compare]
 2906 |                         if (stbl[i] < 0 || stbl[i] >= DTPAGEMAXSLOT) {
      |                                            ~~~~~~~ ^  ~~~~~~~~~~~~~
fs/jfs/jfs_dtree.c:3111:30: error: result of comparison of constant 128 with expression of type 's8' (aka 'signed char') is always false [-Werror,-Wtautological-constant-out-of-range-compare]
 3111 |                 if (stbl[0] < 0 || stbl[0] >= DTPAGEMAXSLOT) {
      |                                    ~~~~~~~ ^  ~~~~~~~~~~~~~

Both the old and the new check were useless, but the previous version
apparently did not lead to the warning.

Remove the extraneous range check for simplicity.

Fixes: cafc6679824a ("jfs: replace hardcoded magic number with DTPAGEMAXSLOT constant")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>