redhat: Fixup self-tests

The merge window exposed a bug in the redhat/self-test/data/create-data.sh
script where the local variables were being reported instead of the test
variables.

Fix the create-data.sh script by moving the reporting of the
Makefile.variables into the dist-dump-variables target.

In addition, the "Makefile contents" test needs to be adjusted because a
"?=" now appears in the redhat/Makefile.

Signed-off-by: Prarit Bhargava prarit@redhat.com