gpu: ion: Add missing argument to WARN call

The condition argument to the WARN call in ion_free is missing. Add the
argument to allow correct printing of warning message.

Change-Id: I158e1a583b7242b2c3209d6ce64dc0b771efeffe
Signed-off-by: Olav Haugan <ohaugan@codeaurora.org>
diff --git a/drivers/gpu/ion/ion.c b/drivers/gpu/ion/ion.c
index 0cec423..6823a5a 100644
--- a/drivers/gpu/ion/ion.c
+++ b/drivers/gpu/ion/ion.c
@@ -484,7 +484,7 @@
 	valid_handle = ion_handle_validate(client, handle);
 	if (!valid_handle) {
 		mutex_unlock(&client->lock);
-		WARN("%s: invalid handle passed to free.\n", __func__);
+		WARN(1, "%s: invalid handle passed to free.\n", __func__);
 		return;
 	}
 	ion_handle_put(handle);