devtools/cocci: make strlcpy replacement smarter

The original coccinelle script worked by replacing instances of
snprintf(.."%s",...) with strlcpy(), but only where the source and dest
parameters were plain identifiers. Allowing expressions for those params
opens up a wide range of other possible changes.

Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>

devtools/cocci/strlcpy.cocci

@@ -1,6 +1,5 @@
 @use_strlcpy@
-identifier src, dst;
-expression size;
+expression src, dst, size;
 @@
 (
 - snprintf(dst, size, "%s", src)