fake-input-accelerometer: Fix test program not working

We forgot to "steal" the pointer before returning from the function
successfully, so the file descriptor was closed. Oops.

Fixes: cc11240 ("fake-input-accelerometer: Simplify error paths")

src/fake-input-accelerometer.c

@@ -157,7 +157,7 @@ setup_uinput (OrientationData *data)
 		return FALSE;
 	}
 
-	data->uinput = fd;
+	data->uinput = g_steal_fd (&fd);
 
 	return TRUE;
 }