rpm2img: ensure /usr/share/bottlerocket exists

[bcressey]

Issue number:
Related: bottlerocket-os/bottlerocket-core-kit#163

Description of changes:
Create the /usr/share/bottlerocket directory before writing any files to it, just in case a package hasn't already created it.

Testing done:
This was annoying to test, given the implicit expectations in rpm2img that a kernel package will be installed, but with some local hacks I was able to confirm that a version of aws-dev which removed the kernel-6.1 package dependency failed later in the script:

  #18 6.266 + KMOD_DIR=/tmp/tmp.93mm5b2Vug/lib/modules
  #18 6.266 + [[ yes == \y\e\s ]]
  #18 6.266 + find /tmp/tmp.93mm5b2Vug/lib/modules -name '*.ko.gz' -exec gunzip '{}' ';'
  #18 6.269 find: '/tmp/tmp.93mm5b2Vug/lib/modules': No such file or directory
  #18 6.270 + cleanup

Said hacks:

❯ git diff
diff --git a/twoliter/embedded/rpm2img b/twoliter/embedded/rpm2img
index 855791c..4d4a592 100755
--- a/twoliter/embedded/rpm2img
+++ b/twoliter/embedded/rpm2img
@@ -1,6 +1,6 @@
 #!/usr/bin/env bash

-set -eu -o pipefail
+set -eux -o pipefail
 shopt -qs failglob

 OUTPUT_FMT="raw"
diff --git a/twoliter/embedded/rpm2kmodkit b/twoliter/embedded/rpm2kmodkit
index 079d98c..1626b4b 100755
--- a/twoliter/embedded/rpm2kmodkit
+++ b/twoliter/embedded/rpm2kmodkit
@@ -31,7 +31,7 @@ mkdir -p "${OUTPUT_DIR}" "${KIT_DIR}/${KMOD_KIT}"
 # Extract any RPMs and find the kernel development archive.
 pushd "${EXTRACT_DIR}" >/dev/null
 find "${ARCHIVE_DIR}" -type f -name '*.rpm' \
-  -exec rpm2cpio {} \; | cpio -idm --quiet
+  -exec rpm2cpio {} \; | cpio -idm --quiet ||:
 find -name 'kernel-devel.tar.xz' \
   -exec mv {} "${KIT_DIR}/${KMOD_KIT}" \;
 popd >/dev/null

Terms of contribution:

By submitting this pull request, I agree that this contribution is dual-licensed under the terms of both the Apache License, version 2.0, and the MIT license.