bnxt_en: Remove unneeded variable in bnxt_hwrm_clear_vnic_filter()

bnxt_en: Remove unneeded variable in bnxt_hwrm_clear_vnic_filter()

After recent refactoring, this function doesn't return error any
more.  Remove the unneeded rc variable and change the function to
void.  The caller is not checking for the return value.

Fixes: 96c9bedc755e ("bnxt_en: Refactor L2 filter alloc/free firmware commands.")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202401041942.qrB1amZM-lkp@intel.com/
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20240105235439.28282-2-michael.chan@broadcom.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>