checkpatch: DEFINE_ macros are real definitions for exports

When we want to confirm an export is directly after its definition we need
to allow for DEFINE_ style macros.  Add these to the execeptions.
Refactor the exceptions.

Signed-off-by: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>