bluetooth: gatt: Fix value returned by db_hash_commit
bluetooth: gatt: Fix value returned by db_hash_commit

Change fixes value returned by db_hash_commit. Returning positive
value leads to settings load failure.

Signed-off-by: Marek Pieta <d27fd21839ecf9c86fcf0dd8561035831899cc5a@nordicsemi.no>

galak/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,galak/zephyr,finikorg/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,galak/zephyr