Lose _r2off in powerpc64 stub names

Lose _r2off in powerpc64 stub names

Not a lot is conveyed by putting _r2off in a stub symbol that can't be
seen by inspecting the stub code or the toc restoring instruction
immediately after a call via such a stub.  Also, we don't distinguish
plt_call stub symbols from plt_call_r2save stub symbols, so this patch
makes long branch and plt branch stub symbols consistent with that
decision.

bfd/
	* elf64-ppc.c (ppc_build_one_stub): Lose "_r2off" in stub symbols.
ld/
	* testsuite/ld-powerpc/elfv2exe.d: Adjust for stub symbol change.
	* testsuite/ld-powerpc/tocopt6.d: Likewise.