dm vdo: fix how dm_kcopyd_client_create() failure is checked

dm_kcopyd_client_create() returns an ERR_PTR so its return must be
checked with IS_ERR().
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Chung Chung <cchung@redhat.com>
Signed-off-by: Matthew Sakai <msakai@redhat.com>

drivers/md/dm-vdo-target.c

@@ -8,6 +8,7 @@
 #include <linux/completion.h>
 #include <linux/delay.h>
 #include <linux/device-mapper.h>
+#include <linux/err.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/spinlock.h>
@@ -1683,8 +1684,11 @@ static int grow_layout(struct vdo *vdo, block_count_t old_size, block_count_t ne
 	/* Make a copy completion if there isn't one */
 	if (vdo->partition_copier == NULL) {
 		vdo->partition_copier = dm_kcopyd_client_create(NULL);
-		if (vdo->partition_copier == NULL)
-			return -ENOMEM;
+		if (IS_ERR(vdo->partition_copier)) {
+			result = PTR_ERR(vdo->partition_copier);
+			vdo->partition_copier = NULL;
+			return result;
+		}
 	}
 
 	/* Free any unused preparation. */

drivers/md/dm-vdo/slab-depot.c

@@ -7,6 +7,7 @@
 
 #include <linux/atomic.h>
 #include <linux/bio.h>
+#include <linux/err.h>
 #include <linux/log2.h>
 #include <linux/min_heap.h>
 #include <linux/minmax.h>
@@ -3445,8 +3446,10 @@ static void initiate_load(struct admin_state *state)
 						   handle_operation_error,
 						   allocator->thread_id, NULL);
 		allocator->eraser = dm_kcopyd_client_create(NULL);
-		if (allocator->eraser == NULL) {
-			vdo_fail_completion(&allocator->completion, -ENOMEM);
+		if (IS_ERR(allocator->eraser)) {
+			vdo_fail_completion(&allocator->completion,
+					    PTR_ERR(allocator->eraser));
+			allocator->eraser = NULL;
 			return;
 		}
 		allocator->slabs_to_erase = get_slab_iterator(allocator);