Jean-Yves Migeon has applied coccinelle to NetBSD, and suggested performing two manual tasks, citing from his email to tech-kern:

• replace all sizeof(fooarray)/sizeof(foo) calculations by its __arraycount() macro equivalent, provided in cdefs.h
• detect places where aprint_* calls could be replaced by aprint_*_dev() to save manual printing of the device driver's name

Update: Jean-Yves' follow-up includes further examples:

• logical not with bitwise "&"
• NULL-pointer dereference after first checking if it's NULL(!?), my favourite (example diff):

   	if (xfer == NULL) {
  -		aprint_error_dev(xfer->fc->bdev, "xfer == NULL\n");
  +		aprint_error("%s: xfer == NULL\n", __func__);
   		return;
   	}