REDHAT: Fix values in Makefile being redefined

JIRA: INTERNAL
Upstream Status: RHEL only

The way the Makefile was set up, calling $(MAKE) here and there, the values of Makefile.rpkg were being loaded multiple times, causing RHDISTGIT_TMP to default to /tmp, instead of the user-defined value in .rhpkg.mk. This fixes that by not re-instantiating make every time.

Signed-off-by: Lucas Zampieri lzampier@redhat.com