and utf8_to_ucs2, be sure to NULL out the return pointer too, rather
than return a pointer to free memory.
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D13917
Use _STANDALONE for guard expression in efichar.[ch] and add efi_char typedef.
clean up boot1.c, and replace for loop in efipart.c with ucs2len().
Reviewed by: imp
Differential Revision: https://reviews.freebsd.org/D13488