eal: fix leak on device event callback unregister

[ upstream commit c78bd27 ]

The event_cb->dev_name is not freed when freeing event_cb,
and this causes a memory leak.

Fixes: a753e53 ("eal: add device event monitor framework")

Signed-off-by: Yunjian Wang <wangyunjian@huawei.com>
Acked-by: Jeff Guo <jia.guo@intel.com>
Acked-by: David Marchand <david.marchand@redhat.com>

lib/librte_eal/common/eal_common_dev.c

@@ -526,6 +526,7 @@ rte_dev_event_callback_unregister(const char *device_name,
 		 */
 		if (event_cb->active == 0) {
 			TAILQ_REMOVE(&dev_event_cbs, event_cb, next);
+			free(event_cb->dev_name);
 			free(event_cb);
 			ret++;
 		} else {