fs: dlm: change plock interrupted message to debug again

[ Upstream commit ea06d4ca ]

This patch reverses the commit bcfad426 ("dlm: improve plock logging
if interrupted") by moving it to debug level and notifying the user an op
was removed.

Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
Stable-dep-of: 57e2c2f2 ("fs: dlm: fix mismatch of plock results from userspace")
Signed-off-by: Sasha Levin <sashal@kernel.org>