nodewatcher: Exit nodewatcher if subscript fails

If a subscript exits with an exit status != 0, its output should not
be used. Because sending incomplete data sets might result in weird
edge cases, the nodewatcher is terminated and the output of other
subscripts is discarded.

Signed-off-by: Fabian Bläse <fabian@blaese.de>
Acked-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>

src/packages/fff/fff-nodewatcher/files/usr/sbin/nodewatcher

@@ -29,6 +29,10 @@ crawl() {
 
 	for f in /usr/lib/nodewatcher.d/*.sh; do
 		tmp="$($f)"
+		if [ $? -ne 0 ]; then
+			debug "Error when executing subscript $f, exiting!"
+			exit 1
+		fi
 		DATA="$DATA$tmp"
 	done