i40e: tame the nvmupdate read and write complaints

The NVMUpdate tool doesn't necessarily know the ReadOnly map of the current
NVM image, and must try reading and writing words that may be protected.
This generates an error out of the Firmware request that the driver logs.
Unfortunately, this ends up spitting out hundreds of bogus read and write
error message that looks rather messy.

This patch checks the error type and under normal conditions will not print
the typical read and write errors during NVMUpdate.  This can be overridden
by enabling the NVM update debugging.  This results in a much less messy log
file, and likely many fewer customer support questions.

Change-ID: Id4ff2e9048c523b0ff503aa5ab181b025ec948ea
Signed-off-by: Shannon Nelson <shannon.nelson@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>