shellcheck (#12258)

* remove unneeded semi-colons at end of line

* fix SC2206: Quote to prevent word splitting/globbing

* fix SC2164: Use 'cd ... || exit' in case cd fails

* fix SC2004: $/${} is unnecessary on arithmetic variables.

* fix SC2155: Declare and assign separately to avoid masking return values.

* fix SC2124: Assigning an array to a string! Assign as array, or use * instead of @ to concatenate.

* fix SC2059: Don't use variables in the printf format string. Use printf "..%s.." "$foo".

* fix SC2076: Don't quote rhs of =~, it'll match literally rather than as a regex.

* fix SC1090: Can't follow non-constant source. Use a directive to specify location.

* fix SC2166: Prefer [ p ] || [ q ] as [ p -o q ] is not well defined.

* SC2223: This default assignment may cause DoS due to globbing. Quote it.

* fix SC2164: Use 'cd ... || exit' or 'cd ... || return' in case cd fails.

* fix SC1117: Backslash is literal in "\n". Prefer explicit escaping: "\\n"

* better handling of branch comapre

* add missing local ver_73 from merge

* remove duplicate definition

scripts/deploy-docs.sh

@@ -37,7 +37,7 @@ EOF
 
 
 mkdir -p out
-cd out
+cd out || exit 1
 
 git init
 git remote add origin "$FULL_REPO"
@@ -46,13 +46,13 @@ git config user.name "librenms-docs"
 git config user.email "travis@librenms.org"
 git checkout master
 
-cd ../
+cd ../ || exit 1
 mkdocs build --clean
 build_result=$?
 
 # Only deploy after merging to master
 if [ "$build_result" == "0" ] && [ "$TRAVIS_PULL_REQUEST" == "false" ] && [ "$TRAVIS_BRANCH" == "master" ]; then
-    cd out/
+    cd out/ || exit 1
     touch .
     git add -A .
     git commit -m "GH-Pages update by travis after $TRAVIS_COMMIT"