build-image: Mark some function local vars local

build-image

@@ -92,6 +92,8 @@ setup_loop() {
 write_meta() {
     local out="$1"
     local image="$2"
+    local image_sha256sum
+    local image_size
 
     image_sha256sum=$(sha256sum "${image}" | sed 's/\([a-f0-9]\+\) .*/\1/')
     image_size=$(stat --format='%s' "${image}")
@@ -108,6 +110,8 @@ EOF
 append_boot_image_meta() {
     local out="$1"
     local image="$2"
+    local image_sha256sum
+    local image_size
 
     image_sha256sum=$(sha256sum "${image}" | sed 's/\([a-f0-9]\+\) .*/\1/')
     image_size=$(stat --format='%s' "${image}")