transfused: when starting, wait up to 2s for pidfile to appear

pidfile appearance is triggered by start-up mount completion.

Signed-off-by: David Sheets <dsheets@docker.com>

alpine/packages/transfused/etc/init.d/transfused

@@ -29,6 +29,8 @@ start()
                 -p "${PIDFILE}" \
                 -l "${STARTUP_LOGFILE}"
 
+	ewaitfile 2 ${PIDFILE}
+
 	eend $? "Failed to start transfused"
 }