Only poll on the NVM semaphore if there's time left on a previous
reservation.  Also, add a little more info to debug messages.

Change-ID: I2439bf870b95a28b810dcb5cca1c06440463cf8a
Signed-off-by: Shannon Nelson <shannon.nelson@intel.com>
Acked-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by: Jim Young <jamesx.m.young@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>