ci: linting

- mount-helper: fix missing `-n`, however seems better to just always fetch a single line here
- debug-network: fix WIP commit using `[[` in a sh script, instead of `[`

commands/debug-network

@@ -2,7 +2,7 @@
 # can't do subshell wrapper, as in [sh] not [bash]
 # do not use any dorothy command, as this is eval'd on environments and situations where dorothy may not be available
 
-if [[ "$*" = '--help' ]]; then
+if [ "$*" = '--help' ]; then
 	cat <<-EOF >/dev/stderr
 		ABOUT:
 		Runs a series of network debugging commands.

commands/mount-helper

@@ -951,7 +951,8 @@ function mount_helper() (
 				# no mounted devices, so try unmount devices
 				eval_capture --statusvar=temp_status --stdoutvar=temp -- get-devices --quiet --result=node --no-mounted --node="$option_share" --filesystem="$mount_type" --label="$option_label" --count="$option_count"
 			fi
-			if [[ -n $temp && $option_label ]]; then
+			if [[ -n $temp ]]; then
+				# get only the first line
 				option_share="$(echo-first-line --stdin <<<"$temp")"
 			fi
 			if [[ $temp_status == 0 && -n $temp ]]; then