qla3xxx: bugfix: Dropping interrupt under heavy network load.

Update the rx queue pointer when exiting NAPI poll rather than
at the end of each iteration.  Remove unnecessary PCI flushes
that occurred after every write.  Now write all regs and
flush once.

Signed-off-by: Ron Mercer <ron.mercer@qlogic.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>