Only build ISO when LINUXKIT_ISO var is set

Signed-off-by: Rahul Ganesh <rahulbabu95@gmail.com>

Author: rahulbabu95

bash/linuxkit.sh

@@ -83,23 +83,6 @@ function linuxkit_build() {
 	declare lk_cache_dir="${CACHE_DIR}/linuxkit"
 	mkdir -p "${lk_cache_dir}"
 
-	declare -a lk_args=(
-		"--docker"
-		"--arch" "${kernel_info['DOCKER_ARCH']}"
-		"--name" "hook"
-		"--cache" "${lk_cache_dir}"
-		"--dir" "${lk_output_dir}"
-		"hook.${inventory_id}.yaml" # the linuxkit configuration file
-	)
-
-	if [[ "${OUTPUT_TARBALL_FILELIST:-"no"}" == "yes" ]]; then
-		log info "OUTPUT_TARBALL_FILELIST=yes; Building Hook (tar/filelist) with kernel ${inventory_id} using linuxkit: ${lk_args[*]}"
-		"${linuxkit_bin}" build "--format" "tar" "${lk_args[@]}"
-	fi
-
-	log info "Building Hook with kernel ${inventory_id} using linuxkit: ${lk_args[*]}"
-	"${linuxkit_bin}" build "--format" "kernel+initrd" "${lk_args[@]}"
-
 	# if LINUXKIT_ISO is set, build an ISO with the kernel and initramfs
 	if [[ -n "${LINUXKIT_ISO}" ]]; then
 		declare lk_iso_output_dir="out"
@@ -117,7 +100,25 @@ function linuxkit_build() {
 
 		log info "Building Hook ISO with kernel ${inventory_id} using linuxkit: ${lk_iso_args[*]}"
 		"${linuxkit_bin}" build "${lk_iso_args[@]}"
+		return 0
 	fi
+	
+	declare -a lk_args=(
+		"--docker"
+		"--arch" "${kernel_info['DOCKER_ARCH']}"
+		"--name" "hook"
+		"--cache" "${lk_cache_dir}"
+		"--dir" "${lk_output_dir}"
+		"hook.${inventory_id}.yaml" # the linuxkit configuration file
+	)
+
+	if [[ "${OUTPUT_TARBALL_FILELIST:-"no"}" == "yes" ]]; then
+		log info "OUTPUT_TARBALL_FILELIST=yes; Building Hook (tar/filelist) with kernel ${inventory_id} using linuxkit: ${lk_args[*]}"
+		"${linuxkit_bin}" build "--format" "tar" "${lk_args[@]}"
+	fi
+
+	log info "Building Hook with kernel ${inventory_id} using linuxkit: ${lk_args[*]}"
+	"${linuxkit_bin}" build "--format" "kernel+initrd" "${lk_args[@]}"
 
 	declare initramfs_path="${lk_output_dir}/hook-initrd.img"
 	# initramfs_path is a gzipped file. obtain the uncompressed byte size, without decompressing it