lpc: flash.sh: add comment

reform2-lpc-fw/flash.sh

 #!/bin/bash
 
+set -e
+
+# replace the x with the drive that LPC actually shows up as (check dmesg -w when plugging in)
+#
+#mount /dev/sdx /mnt
 dd if=bin/firmware.bin of="/mnt/firmware.bin" conv=nocreat,notrunc
 sync
 umount "/mnt"