dm integrity: use kvfree for kvmalloc'd memory

Use kvfree instead of kfree because the array is allocated with kvmalloc.

Fixes: 7eada909bfd7a ("dm: add integrity target")
Cc: stable@vger.kernel.org # v4.12+
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

drivers/md/dm-integrity.c

@@ -2440,7 +2440,7 @@ static void dm_integrity_free_journal_scatterlist(struct dm_integrity_c *ic, str
 	unsigned i;
 	for (i = 0; i < ic->journal_sections; i++)
 		kvfree(sl[i]);
-	kfree(sl);
+	kvfree(sl);
 }
 
 static struct scatterlist **dm_integrity_alloc_journal_scatterlist(struct dm_integrity_c *ic, struct page_list *pl)