Update to how we choose if we are running udevd or dumb-udev

This fixes some issues I found with startup.

overlay/usr/bin/common-functions.sh

@@ -28,7 +28,7 @@ wait_for_x() {
 wait_for_udev() {
     MAX=10
     CT=0
-    while [ ! -f /tmp/.started-udev ]; do
+    while [ ! -e /run/udev/control ]; do
         sleep 1
         CT=$(( CT + 1 ))
         if [ "$CT" -ge "$MAX" ]; then
@@ -36,6 +36,7 @@ wait_for_udev() {
             exit 11
         fi
     done
+    sleep 5
 }
 
 # Wait for dockerd to start

overlay/usr/bin/start-dumb-udev.sh

@@ -17,18 +17,10 @@ _term() {
 trap _term SIGTERM SIGINT
 
 
-# CONFIGURE:
-# Remove lockfile
-rm -f /tmp/.started-udev
-
-
 # EXECUTE PROCESS:
 # Start dumb-udev
-dumb-udev
+dumb-udev &
 dumb_udev_pid=$!
-# Touch lockfile
-sleep 1
-touch /tmp/.started-udev
 
 # WAIT FOR CHILD PROCESS:
 wait "$dumb_udev_pid"

overlay/usr/bin/start-udev.sh

@@ -16,12 +16,6 @@ _term() {
 }
 trap _term SIGTERM SIGINT
 
-
-# CONFIGURE:
-# Remove lockfile
-rm -f /tmp/.started-udev
-
-
 # EXECUTE PROCESS:
 # Start udev
 if command -v udevd &>/dev/null; then
@@ -32,9 +26,6 @@ fi
 # Monitor kernel uevents
 udevadm monitor &
 monitor_pid=$!
-# Touch lockfile
-sleep 1
-touch /tmp/.started-udev
 # Wait for 10 seconds, then request device events from the kernel
 sleep 10
 udevadm trigger