Replace redundant echo's

.utils/subtree-subdir-helper.sh

@@ -12,9 +12,9 @@ subdir="${4}"
 action="${5}"
 
 prev="$(git branch --show-current)"
-temp="$(echo "${repo%/}" | rev | cut -d/ -f1,2 | rev | tr / -)-${branch}"
+temp="$(rev <<< "${repo%/}" | cut -d/ -f1,2 | rev | tr / -)-${branch}"
 fetch="_fetch-${temp}"
-split="_split-${temp}-$(echo "${subdir}" | tr / -)"
+split="_split-${temp}-$(tr / - <<< "${subdir}")"
 git fetch --no-tags "${repo}" "${branch}:${fetch}"
 git checkout "${fetch}"
 git subtree split -P "${subdir}" -b "${split}"
@@ -22,7 +22,7 @@ git checkout "${prev}"
 
 exec 69>&1
 result="$(git subtree "${action}" -P "${path}" "${split}" -m "${action^} ${path} from ${repo}" 2>&1 | tee >(cat - >&69))"
-if echo "$result" | grep "refusing to merge unrelated histories" > /dev/null; then
+if grep "refusing to merge unrelated histories" <<< "$result" > /dev/null; then
     echo "History at ${repo} is unrelated, using quash..."
     git subtree "${action}" -P "${path}" "${split}" -m "${action^} ${path} from ${repo}" --squash
 fi