Revert "Revert "redhat: define _rhel variable because pesign macro now needs it""
Bugzilla: INTERNAL
Upstream Status: RHEL-only
This reverts commit 5c59548640a8018e19f1aea776a5675860e43763.
pesign in CentOS/RHEL 9.0.0 didn't get yet the changes which
made the original revert needed. So revert the revert until pesign
on CentOS/9.0.0 is updated to the same version released on 9.0-beta.
Signed-off-by: Herton R. Krzesinski <herton@redhat.com>