testing: ignore locale when invoking certain shell tools

When testing for specific output of shell tools, we need to ensure that the
system locale (typically engineering English) is active, otherwise we end
up with mismatches when the error messages get translated.

test/valgrindcheck.sh

@@ -59,7 +59,7 @@ killvalgrind () {
         if ps --no-headers ww $pid; then
             for signal in $signals; do
                 echo "valgrind.sh: killing forked process $pid with signal $signal"
-                kill -$signal $pid 2>&1 | grep -v 'No such process'
+                LC_ALL=C kill -$signal $pid 2>&1 | grep -v 'No such process'
             done
         fi
     done

test/wrappercheck.sh

@@ -81,7 +81,7 @@ perl -e "sleep(60); kill(9, $BACKGROUND_PID);" &
 KILL_PID=$!
 set +e
 wait $BACKGROUND_PID
-msg=$(kill -KILL $KILL_PID 2>&1)
+msg=$(LC_ALL=C kill -KILL $KILL_PID 2>&1)
 SUBRET=$?
 if echo "$msg" | grep -q 'No such process'; then
     # Consider this a success.