device-dax: improve fault handler debug output

A couple of minor improvements to the debug output in the fault handlers:

a) Print the region alignment and fault size when we sent a SIGBUS
   because the region alignment is greater than the fault size.
b) Fix the message in the PFN_{DEV|MAP} check.
c) Additionally print the fault size enum value in the huge fault handler.

Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>