fix #H7159 - orc hero can start with lembas wafers

fix #H7159 - orc hero can start with lembas wafers

Orc heroes get an extra food item ("to compensate for generally
inferior equipment") and it could randomly be lembas wafers (or
cram rations), and Ranger heroes always started with cram rations
even when they're orcs.  Fixing the latter was simple, but the
normal race-based substitutions weren't applied to randomly
generated items, so the fix for the former required a bit of code
reorganization in ini_inv().

Elf heroes already get lembas instead of cram; do the reverse for
dwarves (although I don't think this case can happen--no role gets
lembas wafers and only orcs and always-human tourists get random
food); give orc heroes tripe instead of either lembas or cram.