dm-verity: fix section mismatch error

dm-verity: fix section mismatch error

The function "__init dm_verity_init" was calling "__exit
dm_verity_verify_sig_exit" and this triggered section mismatch error.

Fix this by dropping the "__exit" tag on dm_verity_verify_sig_exit.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Fixes: 033724b1c627A ("dm-verity: add dm-verity keyring")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202601210645.11u5Myme-lkp@intel.com/
Closes: https://lore.kernel.org/oe-kbuild-all/202601211041.pcTzwcdp-lkp@intel.com/