redhat: fix make {distg-brew,distg-koji}

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2037486 Upstream Status: RHEL-only

commit e9d430e0915c2cceb13a784361dec335194a4033 Author: Andrea Claudi aclaudi@redhat.com Date: Tue Feb 8 18:08:54 2022 +0100

redhat: fix make {distg-brew,distg-koji}

When Makefile.common is included from makefiles other than the main one,
the GIT macro is not defined, resulting in build fail.

This commit moves the GIT macro definition to the Makefile.common
itself, thus making it defined for each makefile including it.

As a bonus, let's use the GIT macro in koji/Makefile, too.

Co-developed-by: Timothy Redaelli <tredaelli@redhat.com>
Signed-off-by: Andrea Claudi <aclaudi@redhat.com>

Signed-off-by: Andrea Claudi aclaudi@redhat.com