Fixes crashes when there is an error mapping memory. Error mapping physical memory 0x0000004275159040 [0x4000] ERRNO=1 Segmentation fault (core dumped) Change-Id: I5becc0c2870dd97297c4e8d1b101b95b31792ca7 Signed-off-by: Paul Wise <pabs3@bonedaddy.net> Reviewed-on: https://review.coreboot.org/19562 Tested-by: build bot (Jenkins) <no-reply@coreboot.org> Reviewed-by: Philipp Deppenwiese <zaolin.daisuki@gmail.com> Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>