Pylint: use -j 0 arg

"-j 0" runs on the number of CPUs available, just
pass that instead of counting CPUs ourselves.

(This removes a stealthy python2 dependency for us,
too.)

Change-Id: Ib7d90efdbc692fa8e1f42615edec58ba3cef926b

tools/coding-checks.sh

@@ -37,8 +37,7 @@ run_pylint() {
     if [ -n "${files}" ]; then
         echo "Running pylint against:"
         printf "\t%s\n" "${files[@]}"
-        pylint --rcfile=.pylintrc --output-format=colorized ${files} -E \
-            -j `python -c 'import multiprocessing as mp; print(mp.cpu_count())'`
+        pylint --rcfile=.pylintrc --output-format=colorized ${files} -E -j 0
     else
         echo "No python changes in this commit, pylint check not required."
         exit 0