feat(plugins): initrd: fix removal ordering

On amd64, the CPU microcode packages get removed if we rm -rf
${INITRD_ROOT}/lib/firmware *after* we configure the chroot, because
chroot_configure() installs the microcode packages! Clean firmware,
modules first. Then configure.

Signed-off-by: Dilyn Corner <dilyn.corner@canonical.com>

Author: dilyn-corner

snapcraft/parts/plugins/initrd_build.sh

@@ -489,13 +489,13 @@ run() {
 
   # Configure chroot
   [ -e "${BASE_CONFIGURED}" ] || {
-    chroot_configure
-
-    echo "Installing kernel, firmware, and modules into chroot"
     # Remove any existing firmware and modules first
-    rm -rf "${INITRD_ROOT}/usr/lib/firmware/"* \
-           "${INITRD_ROOT}/usr/lib/modules"/*
+    [ ! -e "${INITRD_ROOT}/usr/lib/modules" ]  || rm -rf "${INITRD_ROOT}/usr/lib/modules"
+    [ ! -e "${INITRD_ROOT}/usr/lib/firmware" ] || rm -rf "${INITRD_ROOT}/usr/lib/firmware"
+
+    chroot_configure
     # Install kernel, firmware, modules into chroot
+    echo "Installing kernel, firmware, and modules into chroot"
     cp --archive --link --force "${KERNEL_FIRMWARE}" \
                                 "${KERNEL_MODULES}"  \
                                 "${INITRD_ROOT}/usr/lib"