iavf: fix comments about old bit locks

iavf: fix comments about old bit locks

Bit lock __IAVF_IN_CRITICAL_TASK does not exist anymore since commit
5ac49f3c2702 ("iavf: use mutexes for locking of critical sections").
Adjust the comments accordingly.

Signed-off-by: Michal Schmidt <mschmidt@redhat.com>
Reviewed-by: Wojciech Drewek <wojciech.drewek@intel.com>
Tested-by: Rafal Romanowski <rafal.romanowski@intel.com>
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Link: https://lore.kernel.org/r/20231027175941.1340255-2-jacob.e.keller@intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>