sercon is only used by APM now

ROMFS/px4fmu_common/init.d/rcS

@@ -42,13 +42,18 @@ then
 	sh /fs/microsd/etc/rc.txt
 fi
 
-#
-# Check for USB host
-#
-if [ $USB != autoconnect ]
+# if this is an APM build then there will be a rc.APM script
+# from an EXTERNAL_SCRIPTS build option
+if [ -f /etc/init.d/rc.APM ]
 then
+
+	#
+	# Check for USB host
+	#
+	if [ $USB != autoconnect ]
+	then
 		echo "[init] not connecting USB"
-else
+	else
 		if sercon
 		then
 			echo "[init] USB interface connected"
@@ -60,12 +65,8 @@ else
 				echo "[init] No USB connected"
 			fi
 		fi
-fi
+	fi
 
-# if this is an APM build then there will be a rc.APM script
-# from an EXTERNAL_SCRIPTS build option
-if [ -f /etc/init.d/rc.APM ]
-then
 	echo Running rc.APM
 	# if APM startup is successful then nsh will exit
 	sh /etc/init.d/rc.APM