igb: move initialization of number of queues into set_interrupt_capability

This patch moves the initialization of the number of queues into
set_interrupt_capability.  This allows the number of queues to increase in
the unlikely event that the system initially fails to allocate enough msi-x
interrupts, does a suspend/resume, and then can allocate enough interrupts
on resume.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>