ROMFS: rcS disable simplistic SD I/O test

- this was added when trying to identify SD card issues at boot and
trigger a format, but didn't provide any value

ROMFS/px4fmu_common/init.d/rcS

@@ -72,28 +72,7 @@ then
 			umount /fs/microsd
 
 		else
-			# very basic I/O test
-			set PX4_INIT_TEST_FILE "/fs/microsd/.px4_init_test_file"
-			date >> $PX4_INIT_TEST_FILE
-
-			if [ $? -eq 0 -a -f $PX4_INIT_TEST_FILE ]
-			then
-				cat $PX4_INIT_TEST_FILE
-				rm $PX4_INIT_TEST_FILE
-
-				if [ $? -eq 0 -a ! -f $PX4_INIT_TEST_FILE ]
-				then
-					set SDCARD_AVAILABLE yes
-				fi
-			fi
-			unset PX4_INIT_TEST_FILE
-
-			if [ $SDCARD_AVAILABLE = no ]
-			then
-				echo "ERROR [init] card I/O failure, formatting"
-				set SDCARD_FORMAT yes
-				umount /fs/microsd
-			fi
+			set SDCARD_AVAILABLE yes
 		fi
 	fi