multilib.eclass: save/restore AR, NM, RANLIB, OBJDUMP, STRIP, bug #724558
A follow-up to commit
dd35b529194fdc
("populate AR, NM, RANLIB, OBJDUMP, STRIP, bug #724558")
Before the change AR and friends were set for non-default ABI
and were not restored to defaults for next native ABI.
It should not be a problem for default case as both do match.
For consistency with other variables now we restore possibly
unset values for native ABI.
Noticed by Arfrever Frehtes Taifersar Arahesis.
Reported-by: Arfrever Frehtes Taifersar Arahesis
Bug: https://bugs.gentoo.org/724558
Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org>