Make the c and ac scripts work with sh and without bin in PATH

bin/ac

Index: bin/ac
diff --git a/bin/ac b/bin/ac
index 05fd6051455534232efdb58d0b942ae1f6e3bd58..30e95346124e4d10d4aa23502dffe2adbcc5eee3 100755
--- a/bin/ac
+++ b/bin/ac
@@ -6,7 +6,7 @@ BRANCH=$(git branch | grep \* | cut -d" "  -f 2)
 CLEAN=${CLEAN-clean}
 SAMPLES=100
 
-if [ $BRANCH == $CLEAN ]; then
+if [ "$BRANCH" = "$CLEAN" ]; then
     echo "Comparing $BRANCH to itself."
     exit 1
 fi
@@ -23,4 +23,4 @@ git checkout $BRANCH
 platform_tools/android/bin/android_ninja -t Release nanobench
 platform_tools/android/bin/android_run_skia -t Release nanobench $@ --skps /data/local/tmp/skps -i /data/local/tmp/resources --samples $SAMPLES -v > $BRANCH.log
 
-compare $CLEAN.log $BRANCH.log
+./bin/compare $CLEAN.log $BRANCH.log