ci: Fix shellcheck warnings in firmware download

Signed-off-by: Daniel Stone <daniels@collabora.com>
Fixes: 0441202d6b ("ci: add firmware files to rootfs")
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/30978>

.gitlab-ci/container/get-firmware-from-source.sh

@@ -1,10 +1,13 @@
 #!/usr/bin/env bash
+# shellcheck disable=SC2046 # we want to arg-split FIRMWARE_FILES
+# shellcheck disable=SC2086 # as above
+# shellcheck disable=SC2116 # as above
 
 set -e
 
 ROOTFS=$1
 FIRMWARE_FILES=$2
-FIRMWARE=$(jq -s '.' $FIRMWARE_FILES)
+FIRMWARE=$(jq -s '.' $(echo "$FIRMWARE_FILES"))
 
 if [ -z "$FIRMWARE" ] || [ "$(echo "$FIRMWARE" | jq '. | length')" -eq 0 ]; then
   echo "FIRMWARE is not set or is empty."

.gitlab-ci/container/lava_build.sh

@@ -2,6 +2,7 @@
 # shellcheck disable=SC1091 # The relative paths in this file only become valid at runtime.
 # shellcheck disable=SC2034 # Variables are used in scripts called from here
 # shellcheck disable=SC2086 # we want word splitting
+# shellcheck disable=SC2016 # non-expanded variables are intentional
 # When changing this file, you need to bump the following
 # .gitlab-ci/image-tags.yml tags:
 # KERNEL_ROOTFS_TAG