add a trivial patch style checker

We are seeing increasing levels of minor patch style violations in submissions
to the mailing lists as well as making it into the tree.  These detract from
the quality of the submission and cause unnessary work for reviewers.

As a first step package up the current state of the patch style checker and
include it in the kernel tree.  Add instructions suggesting running it on
submissions.  This adds version v0.01 of the checkpatch.pl script.

Signed-off-by: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Joel Schopp <jschopp@austin.ibm.com>
Cc: Randy Dunlap <rdunlap@xenotime.net>
Cc: Dave Jones <davej@codemonkey.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/Documentation/SubmitChecklist b/Documentation/SubmitChecklist
index 3af3e65..6ebffb5 100644
--- a/Documentation/SubmitChecklist
+++ b/Documentation/SubmitChecklist
@@ -84,3 +84,9 @@
 24: Avoid whitespace damage such as indenting with spaces or whitespace
     at the end of lines.  You can test this by feeding the patch to
     "git apply --check --whitespace=error-all"
+
+25: Check your patch for general style as detailed in
+    Documentation/CodingStyle.  Check for trivial violations with the
+    patch style checker prior to submission (scripts/checkpatch.pl).
+    You should be able to justify all violations that remain in
+    your patch.