[PATCH] SubmitChecklist update

Sing the praises of `gcc -W'.  Would have prevented that blockdev direct-IO
bug.

Cc: "Chen, Kenneth W" <kenneth.w.chen@intel.com>
Cc: "Randy.Dunlap" <rdunlap@xenotime.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Documentation/SubmitChecklist

@@ -72,3 +72,7 @@ kernel patches.
 
     If the new code is substantial, addition of subsystem-specific fault
     injection might be appropriate.
+
+22: Newly-added code has been compiled with `gcc -W'.  This will generate
+    lots of noise, but is good for finding bugs like "warning: comparison
+    between signed and unsigned".