init.common.usb.rc: remove duplicate trigger

the same trigger of "on property:init.svc.adbd=stopped"
is defined in the file of system/core/rootdir/init.usb.configfs.rc here:
https://android.googlesource.com/platform/system/core/+/master/rootdir/init.usb.configfs.rc#15

Test: manually with hikey

Change-Id: I05348ceab39a7090135d59e54df77a818149b88e
Signed-off-by: Yongqin Liu <yongqin.liu@linaro.org>
diff --git a/init.common.usb.rc b/init.common.usb.rc
index ff3d807..7351f8d 100644
--- a/init.common.usb.rc
+++ b/init.common.usb.rc
@@ -29,9 +29,6 @@
     write /config/usb_gadget/g1/os_desc/use 0
     setprop sys.usb.ffs.ready 0
 
-on property:init.svc.adbd=stopped
-    setprop sys.usb.ffs.ready 0
-
 on property:sys.usb.config=mtp && property:sys.usb.configfs=1
     write /config/usb_gadget/g1/functions/mtp.gs0/os_desc/interface.MTP/compatible_id "MTP"
     write /config/usb_gadget/g1/os_desc/use 1