checkpatch: structure member assignments are not complex

Ensure we do not trigger the complex macros checks on structure member
assignment, for example:

	#define foo .bar = 10

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>