lib/55657: libsa ffs support is not endian independent

[jmcneill%invisible.ca@localhost]

>Number:         55657
>Category:       lib
>Synopsis:       libsa ffs support is not endian independent
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    lib-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sun Sep 13 20:10:01 +0000 2020
>Originator:     Jared McNeill
>Release:        9.99.72
>Organization:
>Environment:
NetBSD 9.99.72 (GENERIC64) #173: Sun Sep 13 16:29:07 ADT 2020
>Description:
LIBSA_BIENDIAN_SUPPORT allows for loading opposite endian kernels than the bootloader, but the ffs code only allows for loading kernels from a partition that is the same endian as the bootloader.
>How-To-Repeat:

>Fix: