The tx interrupt is of edge type, and in case such interrupt is triggered
while it is masked it will not be handled even after tx interrupts are
re-enabled in the end of NAPI poll.
This will cause tx network to stop in the following scenario:
 * Rx is being handled, hence interrupts are masked.
 * Tx interrupt is triggered after checking if there is some tx to handle
   and before re-enabling the interrupts.
In this situation only rx transaction will release tx requests.

In order to handle the tx that was missed( if there was one ),
a NAPI reschdule was added after enabling the interrupts.
Signed-off-by: Elad Kanfi <eladkan@mellanox.com>
Acked-by: Noam Camus <noamca@mellanox.com>
Acked-by: Gilad Ben-Yossef <giladby@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>