BUILD_BUG_ON() causes a syntax error to detect coding errors.  So it
causes sparse to detect an error too.  This reduces sparse's usefulness.

This patch makes a dummy BUILD_BUG_ON() definition for sparse.
Signed-off-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>