Firstrun was failing when booting from eMMC, changing detection method

scripts/firstrun

@@ -177,12 +177,12 @@ autodetect_sunxi() {
 
 do_expand_rootfs() {
 	# get device node for boot media
-	DEVICE="/dev/"$(lsblk -idn -o NAME | grep mmcblk0)
+	DEVICE="/dev/"$(lsblk -idn -o NAME | grep -w mmcblk0)
 	if [ "${DEVICE}" = "/dev/" ]; then return ; fi
 	QUOTED_DEVICE=$(echo "${DEVICE}" | sed 's:/:\\\/:g')
 
 	# get count of partitions and their boundaries
-	PARTITIONS=$(( $(grep -c ${DEVICE##*/} /proc/partitions) - 1 ))
+	PARTITIONS=$(( $(grep -c ${DEVICE##*/}p /proc/partitions) ))
 	PARTSTART=$(parted ${DEVICE} unit s print -sm | tail -1 | cut -d: -f2 | sed 's/s//') # start of first partition
 	PARTEND=$(parted ${DEVICE} unit s print -sm | head -3 | tail -1 | cut -d: -f3 | sed 's/s//') # end of first partition
 	STARTFROM=$(( ${PARTEND} + 1 ))