*new* check_resource_size(): prod people to use resource_size()

*new* check_resource_size():  prod people to use resource_size()

There is a kernel function called resource_size() and this check
encourages people to use it.  Normally people calculate their resource
size by doing "end - start" but the correct way is to do "end - start + 1".

This check produces at least two false positives:
netxen has an end which is 1 higher than normal so end - start works.
some other driver does "size - 3" depending on the config.

But generally this check works surprisingly well.

Signed-off-by: Dan Carpenter <error27@gmail.com>