board/common: let dagger script set LOG_PID with parent PID

This adds [PPID] to the syslog lines to the dagger script.  After all,
the dagger script is a proxy for confd, so when reading the logs it
seems natural to see the PID of confd rather than a script that will
die soon anyway.

Signed-off-by: Joachim Wiberg <troglobit@gmail.com>

board/common/rootfs/sbin/dagger

@@ -7,7 +7,7 @@ inform()
     local level="$1"
     shift
 
-    logger -p "daemon.$level" -t dagger -c $LOGGER_STDOUT "$@"
+    logger -p "daemon.$level" -I $PPID -t dagger -c $LOGGER_STDOUT "$@"
 }
 
 abort()