Fix shellcheck failures on clean.sh and cache_go_dirs.sh

hack/.shellcheck_failures

@@ -30,8 +30,6 @@
 ./hack/lib/swagger.sh
 ./hack/lib/test.sh
 ./hack/lib/version.sh
-./hack/make-rules/clean.sh
-./hack/make-rules/helpers/cache_go_dirs.sh
 ./hack/make-rules/make-help.sh
 ./hack/make-rules/test.sh
 ./hack/make-rules/update.sh

hack/make-rules/clean.sh

@@ -18,7 +18,7 @@ set -o errexit
 set -o nounset
 set -o pipefail
 
-KUBE_ROOT=$(dirname "${BASH_SOURCE}")/../..
+KUBE_ROOT=$(dirname "${BASH_SOURCE[0]}")/../..
 source "${KUBE_ROOT}/hack/lib/util.sh"
 
 CLEAN_PATTERNS=(
@@ -28,11 +28,11 @@ CLEAN_PATTERNS=(
   "test/e2e/generated/bindata.go"
 )
 
-for pattern in ${CLEAN_PATTERNS[@]}; do
-  for match in $(find "${KUBE_ROOT}" -iregex "^${KUBE_ROOT}/${pattern}$"); do
+for pattern in "${CLEAN_PATTERNS[@]}"; do
+  while IFS=$'\n' read -r -d match; do
     echo "Removing ${match#${KUBE_ROOT}\/} .."
     rm -rf "${match#${KUBE_ROOT}\/}"
-  done
+  done <   <(find "${KUBE_ROOT}" -iregex "^${KUBE_ROOT}/${pattern}$")
 done
 
 # ex: ts=2 sw=2 et filetype=sh

hack/make-rules/helpers/cache_go_dirs.sh

@@ -28,7 +28,7 @@ if [[ -z "${1:-}" ]]; then
 fi
 CACHE="$1"; shift
 
-trap "rm -f '${CACHE}'" HUP INT TERM ERR
+trap 'rm -f "${CACHE}"' HUP INT TERM ERR
 
 # This is a partial 'find' command.  The caller is expected to pass the
 # remaining arguments.
@@ -62,8 +62,8 @@ if [[ -f "${CACHE}" ]]; then
     N=$(kfind -type d -newer "${CACHE}" -print -quit | wc -l)
     [[ "${N}" == 0 ]] && NEED_FIND=false
 fi
-mkdir -p $(dirname "${CACHE}")
-if $("${NEED_FIND}"); then
+mkdir -p "$(dirname "${CACHE}")"
+if ${NEED_FIND}; then
     kfind -type f -name \*.go  \
         | sed 's|/[^/]*$||'    \
         | sed 's|^./||'        \