ixgbe: Place SWFW semaphore in known valid state at probe

It is possible on some HW that a system reset could occur when we are
holding the SWFW semaphore lock.  So next time the driver was loaded we
would see it incorrectly as locked. This patch will recover from that state
by: Attempting to acquire the semaphore and then regardless of whether or
not it was acquire we immediately release it. This will force us into
a known good state.

Signed-off-by: Don Skidmore <donald.c.skidmore@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>