ucounts: Backport fixes for ucount rlimits

Bugzilla: https://bugzilla.redhat.com/2061724 Upstream Status: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git

This is another batch of rlimits and ucounts fixes from upstream.

Signed-off-by: Alexey Gladkov agladkov@redhat.com