[PATCH] submit checklist: mention headers_check

Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/Documentation/SubmitChecklist b/Documentation/SubmitChecklist
index a6cb6ff..7ac61f6 100644
--- a/Documentation/SubmitChecklist
+++ b/Documentation/SubmitChecklist
@@ -64,3 +64,5 @@
 
 19: All new userspace interfaces are documented in Documentation/ABI/.
     See Documentation/ABI/README for more information.
+
+20: Check that it all passes `make headers_check'.