In usr/sbin/rear
avoid ShellCheck
SC1075: Use 'elif' instead of 'else if' (or put 'if' on new line if nesting)
https://github.com/koalaman/shellcheck/wiki/SC1075
and fixed ShellCheck
SC2145: Argument mixes string and array. Use * or separate argument
https://github.com/koalaman/shellcheck/wiki/SC2145
cf. #1040