dm-integrity: set ti->error on memory allocation failure

The dm-integrity target didn't set the error string when memory
allocation failed. This patch fixes it.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org

drivers/md/dm-integrity.c

@@ -5081,16 +5081,19 @@ static int dm_integrity_ctr(struct dm_target *ti, unsigned int argc, char **argv
 
 		ic->recalc_bitmap = dm_integrity_alloc_page_list(n_bitmap_pages);
 		if (!ic->recalc_bitmap) {
+			ti->error = "Could not allocate memory for bitmap";
 			r = -ENOMEM;
 			goto bad;
 		}
 		ic->may_write_bitmap = dm_integrity_alloc_page_list(n_bitmap_pages);
 		if (!ic->may_write_bitmap) {
+			ti->error = "Could not allocate memory for bitmap";
 			r = -ENOMEM;
 			goto bad;
 		}
 		ic->bbs = kvmalloc_array(ic->n_bitmap_blocks, sizeof(struct bitmap_block_status), GFP_KERNEL);
 		if (!ic->bbs) {
+			ti->error = "Could not allocate memory for bitmap";
 			r = -ENOMEM;
 			goto bad;
 		}