dm: return early from dm_pr_call() if DM device is suspended

stable inclusion
from stable-v4.19.256
commit 4f040ba9f15d047f173ecc01d3bba3d1e9fbee08
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I5UQH4


CVE: NA

--------------------------------

[ Upstream commit e120a5f1 ]

Otherwise PR ops may be issued while the broader DM device is being
reconfigured, etc.

Fixes: 9c72bad1 ("dm: call PR reserve/unreserve on each underlying device")
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Yongqiang Liu <liuyongqiang13@huawei.com>