qseecom: fix listener unregistration issue

When listener unregister thread wakes up due to some system signals,
but not because ioctl_cnt <=1, it should return directly, instead of
continuing to remove listener list entry, which will lead kernel panic
when another listener receive thread accesses this freed entry.

Change-Id: I6ff97c56867d008232d7c50b22b372b0856c8dff
Signed-off-by: Zhen Kong <zkong@codeaurora.org>

drivers/misc/qseecom.c

@@ -1257,7 +1257,7 @@ static int qseecom_unregister_listener(struct qseecom_dev_handle *data)
 				atomic_read(&data->ioctl_count) <= 1)) {
 			pr_err("Interrupted from abort\n");
 			ret = -ERESTARTSYS;
-			break;
+			return ret;
 		}
 	}