Makefile: remove redundant munging of @@INSTLIBDIR@@
Junio originally added this in
f6276fe159 for use in `unshift @INC,
'@@INSTLIBDIR@@'' in git-fmt-merge-msg.perl. That program was since
then rewritten in C in
00449f992b. And since
6fcca938b0 all Perl
programs use `use lib' to set their @INC path.
There's been no @@INSTLIBDIR@@ in any Perl script to replace since
then. So there's no reason to keep it around.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>