ice: fix rate limit update after coalesce change

If the adaptive settings are changed with
ethtool -C ethx adaptive-rx off adaptive-tx off
then the interrupt rate limit should be maintained as a user set value,
but only if BOTH adaptive settings are off. Fix a bug where the rate
limit that was being used in adaptive mode was staying set in the
register but was not reported correctly by ethtool -c ethx. Due to long
lines include a small refactor of q_vector variable.

Fixes: b8b47723 ("ice: refactor interrupt moderation writes")
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by: Gurucharan G <gurucharanx.g@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>