crypto: ccree - fix backlog memory leak

Fix brown paper bag bug of not releasing backlog list item buffer
when backlog was consumed causing a memory leak when backlog is
used.

Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com>
Cc: stable@vger.kernel.org # v4.19+
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/ccree/cc_request_mgr.c

@@ -404,6 +404,7 @@ static void cc_proc_backlog(struct cc_drvdata *drvdata)
 		spin_lock(&mgr->bl_lock);
 		list_del(&bli->list);
 		--mgr->bl_len;
+		kfree(bli);
 	}
 
 	spin_unlock(&mgr->bl_lock);