cmd/mr_create_test: fix test text wrt number of commits
cmd/mr_create_test: fix test text wrt number of commits

The recent changes corrected the counting of number of commits, which is
now breaking the old test behavior. This patch updates it.

Signed-off-by: Bruno Meneguele <82c7731bc2625bcbab88bc571aee6631ba3f66f3@redhat.com>

zaquestion/lab,zaquestion/lab