boot-directdisk.bbclass: Fix media generation problems with vmdk

The various populate methods need to accept a path as an argument vs
using hard expanded variables.  In the case of the boot-directdisk
class it uses a different path for HDDDIR but it gets eclipsed by the
the class definition at the point in time ${HDDDIR} gets expanded.

The logical fix is to pass the arguments to the functions as opposed
to using globally expanded variables from the class definitions.

This patch changes 3 things:
1) syslinux_hddimg_populate takes an argument for the destination
2) syslinux_iso_populate takes an argument for the destination
3) populate is changed to boot_direct_populate because there
   was a conflict with it overriding the populate in bootimg.bbclass

[YOCTO #3994]

(From OE-Core rev: 63d164b755b984021f7e3cdba7280918ded6e821)

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Saul Wold <sgw@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/classes/boot-directdisk.bbclass

@@ -61,15 +61,15 @@ DISK_SIGNATURE ?= "${DISK_SIGNATURE_GENERATED}"
 SYSLINUX_ROOT ?= "root=/dev/sda2"
 SYSLINUX_TIMEOUT ?= "10"
 
-populate() {
-	DEST=$1
-	install -d ${DEST}
+boot_direct_populate() {
+	dest=$1
+	install -d $dest
 
 	# Install bzImage, initrd, and rootfs.img in DEST for all loaders to use.
-	install -m 0644 ${STAGING_KERNEL_DIR}/bzImage ${DEST}/vmlinuz
+	install -m 0644 ${STAGING_KERNEL_DIR}/bzImage $dest/vmlinuz
 
 	if [ -n "${INITRD}" ] && [ -s "${INITRD}" ]; then
-		install -m 0644 ${INITRD} ${DEST}/initrd
+		install -m 0644 ${INITRD} $dest/initrd
 	fi
 
 }
@@ -79,13 +79,13 @@ build_boot_dd() {
 	HDDIMG="${S}/hdd.image"
 	IMAGE=${DEPLOY_DIR_IMAGE}/${IMAGE_NAME}.hdddirect
 
-	populate ${HDDDIR}
+	boot_direct_populate $HDDDIR
 
 	if [ "${PCBIOS}" = "1" ]; then
-		syslinux_hddimg_populate
+		syslinux_hddimg_populate $HDDDIR
 	fi
 	if [ "${EFI}" = "1" ]; then
-		grubefi_hddimg_populate
+		grubefi_hddimg_populate $HDDDIR
 	fi
 
 	BLOCKS=`du -bks $HDDDIR | cut -f 1`