crypto: jitter - Use kvfree_sensitive() to fix Coccinelle warning

Replace memzero_explicit() and kvfree() with kvfree_sensitive() to fix
the following Coccinelle/coccicheck warning reported by
kfree_sensitive.cocci:

	WARNING opportunity for kfree_sensitive/kvfree_sensitive
Signed-off-by: Thorsten Blum <thorsten.blum@toblux.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto/jitterentropy-kcapi.c

@@ -61,8 +61,7 @@ void *jent_kvzalloc(unsigned int len)
 
 void jent_kvzfree(void *ptr, unsigned int len)
 {
-	memzero_explicit(ptr, len);
-	kvfree(ptr);
+	kvfree_sensitive(ptr, len);
 }
 
 void *jent_zalloc(unsigned int len)