be2net: fix a possible events_get() race on BE2

On BE2 chip, an interrupt being raised even when EQ is in un-armed state has
been observed a few times.  This is not expected and has never been
observed on BE3/Lancer chips.

As a consequence, be_msix()::events_get() and be_poll()::events_get()
can race and notify an EQ wrongly causing a CEV UE. The other possible
side-effect would be traffic stalling because after notifying EQ,
napi_schedule() is ignored as NAPI is already running.

This patch fixes this issue by counting events only in be_poll().

Signed-off-by: Sathya Perla <sathya.perla@emulex.com>
Signed-off-by: David S. Miller <davem@davemloft.net>