Fix R_PPC64_{JMP_IREL,IRELATIVE} handling in dl-conflict.c.

Fix R_PPC64_{JMP_IREL,IRELATIVE} handling in dl-conflict.c.

I've just committed STT_GNU_IFUNC ppc/ppc64 support into prelink,
and this patch is needed on the glibc side.  Without it ld.so segfaults,
as in dl-conflict.c sym_map is always NULL.  While dl-machine.h could use
RESOLVE_CONFLICT_FIND_MAP macro to compute it, it doesn't make sense,
because with prelink we know it is already properly relocated (all relative
relocations are applied by prelink).