common/rc: refactor _require_{ext2,tmpfs} helpers

Combine these two helpers into a single generic function so that we can
use it in the next patch to test a regression when running overlayfs
atop xfs.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Eryu Guan <guaneryu@gmail.com>
Signed-off-by: Eryu Guan <guaneryu@gmail.com>
7 files changed