testdisplay: remove wrong return statement

From: Paulo Zanoni <[email protected]>

It seems that the kernel patches required by the TEST_PLANES feature are still not upstream, so I didn't test this patch.

---
 tests/testdisplay.c |    1 -
 1 files changed, 0 insertions(+), 1 deletions(-)

index 69dbf42..d650537 100644
@@ -677,7 +677,6 @@ connector_find_plane(struct connector *c)
 		drmModeFreePlane(ovr);
 	}
 
-	return 4;
 	return id;
 }
 

1.7.4.1