rootdir: convert all usages of $prop to ${prop}

Change-Id: Ic2472606e869d23c0f499a192cd7bb21ca3cf5b5
Signed-off-by: Dima Zavin <dima@android.com>
diff --git a/rootdir/init.rc b/rootdir/init.rc
index 8041b93..21f54d3 100644
--- a/rootdir/init.rc
+++ b/rootdir/init.rc
@@ -303,7 +303,7 @@
     stop adbd
     write /sys/class/android_usb/android0/enable 0
     write /sys/class/android_usb/android0/bDeviceClass 0
-    setprop sys.usb.state $sys.usb.config
+    setprop sys.usb.state ${sys.usb.config}
 
 # adb only USB configuration
 # This should only be used during device bringup
@@ -312,34 +312,34 @@
     write /sys/class/android_usb/android0/enable 0
     write /sys/class/android_usb/android0/idVendor 18d1
     write /sys/class/android_usb/android0/idProduct D002
-    write /sys/class/android_usb/android0/functions $sys.usb.config
+    write /sys/class/android_usb/android0/functions ${sys.usb.config}
     write /sys/class/android_usb/android0/enable 1
     start adbd
-    setprop sys.usb.state $sys.usb.config
+    setprop sys.usb.state ${sys.usb.config}
 
 # USB accessory configuration
 on property:sys.usb.config=accessory
     write /sys/class/android_usb/android0/enable 0
     write /sys/class/android_usb/android0/idVendor 18d1
     write /sys/class/android_usb/android0/idProduct 2d00
-    write /sys/class/android_usb/android0/functions $sys.usb.config
+    write /sys/class/android_usb/android0/functions ${sys.usb.config}
     write /sys/class/android_usb/android0/enable 1
-    setprop sys.usb.state $sys.usb.config
+    setprop sys.usb.state ${sys.usb.config}
 
 # USB accessory configuration, with adb
 on property:sys.usb.config=accessory,adb
     write /sys/class/android_usb/android0/enable 0
     write /sys/class/android_usb/android0/idVendor 18d1
     write /sys/class/android_usb/android0/idProduct 2d01
-    write /sys/class/android_usb/android0/functions $sys.usb.config
+    write /sys/class/android_usb/android0/functions ${sys.usb.config}
     write /sys/class/android_usb/android0/enable 1
     start adbd
-    setprop sys.usb.state $sys.usb.config
+    setprop sys.usb.state ${sys.usb.config}
 
 # Used to set USB configuration at boot and to switch the configuration
 # when changing the default configuration
 on property:persist.sys.usb.config=*
-    setprop sys.usb.config $persist.sys.usb.config
+    setprop sys.usb.config ${persist.sys.usb.config}
 
 ## Daemon processes to be run by init.
 ##