ionic: minimal work with 0 budget

We should be doing as little as possible besides freeing Tx
space when our napi routines are called with budget of 0, so
jump out before doing anything besides Tx cleaning.

See commit afbed3f7 ("net/mlx5e: do as little as possible in napi poll when budget is 0")
for more info.

Fixes: fe8c30b5

 ("ionic: separate interrupt for Tx and Rx")
Reviewed-by: Brett Creeley <brett.creeley@amd.com>
Signed-off-by: Shannon Nelson <shannon.nelson@amd.com>
Link: https://lore.kernel.org/r/20240210001307.48450-1-shannon.nelson@amd.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>