Staging: zcache: signedness bug in tmem_get()

"ret" needs to be signed for the error handling to work properly.
Signed-off-by: NDan Carpenter <error27@gmail.com>
Acked-by: NDan Magenheimer <dan.magenheimer@oracle.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

drivers/staging/zcache/tmem.c

@@ -604,7 +604,7 @@ int tmem_get(struct tmem_pool *pool, struct tmem_oid *oidp, uint32_t index,
 	struct tmem_obj *obj;
 	void *pampd;
 	bool ephemeral = is_ephemeral(pool);
-	uint32_t ret = -1;
+	int ret = -1;
 	struct tmem_hashbucket *hb;
 	bool free = (get_and_free == 1) || ((get_and_free == 0) && ephemeral);
 	bool lock_held = false;