nvmecontrol: Make the error log page work on native format

As the number of page types proliferates, it becomes untennable to
convert them in read_logpage (especailly since new UUID page types will
need to be supported). Convert the error page printing code to operate
on little endian data.

Sponsored by: Netflix
Reviewed by: chuck
Differential Revision: https://reviews.freebsd.org/D44680

(cherry picked from commit 85656a9a015339f3d412e5b1888e798bb3e7d4ba)