fm10k: Fix handling of NAPI budget when multiple queues are enabled per vector

fm10k: Fix handling of NAPI budget when multiple queues are enabled per vector

BugLink: http://bugs.launchpad.net/bugs/1536475
This patch corrects an issue in which the polling routine would increase
the budget for Rx to at least 1 per queue if multiple queues were present.
This would result in Rx packets being processed when the budget was 0 which
is meant to indicate that no Rx can be handled.

Signed-off-by: Alexander Duyck <aduyck@mirantis.com>
Tested-by: Krishneil Singh <Krishneil.k.singh@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
(cherry picked from commit 9f872986479b6e0543eb5c615e5f9491bb04e5c1)
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>