[PATCH] dm: fix err_cast.cocci warnings

[kernel test robot]

From: kernel test robot <lkp@xxxxxxxxx>

drivers/md/dm.c:2204:12-19: WARNING: ERR_CAST can be used with ksm


 Use ERR_CAST inlined function instead of ERR_PTR(PTR_ERR(...))

Generated by: scripts/coccinelle/api/err_cast.cocci

CC: Satya Tangirala <satyat@xxxxxxxxxx>
Signed-off-by: kernel test robot <lkp@xxxxxxxxx>
---

url:    https://github.com/0day-ci/linux/commits/Satya-Tangirala/add-support-for-inline-encryption-to-device-mapper/20201016-054900
base:   https://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm.git for-next

 dm.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -2201,7 +2201,7 @@ static struct dm_table *__bind(struct ma
 
 	ksm = dm_init_inline_encryption(md, t);
 	if (IS_ERR(ksm)) {
-		old_map = ERR_PTR(PTR_ERR(ksm));
+		old_map = ERR_CAST(ksm);
 		goto out;
 	}