DEV: coccinelle: Add ha_free.cocci

Taken from 61cfdf4fd8a93dc6fd9922d5b309a71bdc7d2853.
diff --git a/dev/coccinelle/ha_free.cocci b/dev/coccinelle/ha_free.cocci
new file mode 100644
index 0000000..0019039
--- /dev/null
+++ b/dev/coccinelle/ha_free.cocci
@@ -0,0 +1,6 @@
+@ rule @
+expression E;
+@@
+- free(E);
+- E = NULL;
++ ha_free(&E);