Making sure cameraserver can write into camera-daemon cpuset

If multiple writepids, all must be in one line to take effect. Else,
only the last one will take effect.

bug: 30192722
bug: 28312446
Change-Id: Icbcdefec58346d5c7258b51055de96ec8de8dd65
diff --git a/camera/cameraserver/cameraserver.rc b/camera/cameraserver/cameraserver.rc
index c1dad2c..fea5a1d 100644
--- a/camera/cameraserver/cameraserver.rc
+++ b/camera/cameraserver/cameraserver.rc
@@ -3,5 +3,4 @@
     user cameraserver
     group audio camera input drmrpc
     ioprio rt 4
-    writepid /dev/cpuset/camera-daemon/tasks
-    writepid /dev/stune/top-app/tasks
+    writepid /dev/cpuset/camera-daemon/tasks /dev/stune/top-app/tasks