checkpatch: reduce MAINTAINERS update message frequency

When files are being added/moved/deleted and a patch contains an update to
the MAINTAINERS file, assume it's to update the MAINTAINERS file correctly
and do not emit the "does MAINTAINERS need updating?" message.

Reported by many people.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: NMarkus Armbruster <armbru@redhat.com>
Reviewed-by: NThomas Huth <thuth@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Message-id: 20180430124651.10340-6-stefanha@redhat.com
(cherry picked from e0d975b1b439c4fef58fbc306c542c94f48bb849)
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: NThomas Huth <thuth@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

scripts/checkpatch.pl

@@ -1390,6 +1390,12 @@ sub process {
 			}
 		}
 
+# Check if MAINTAINERS is being updated.  If so, there's probably no need to
+# emit the "does MAINTAINERS need updating?" message on file add/move/delete
+		if ($line =~ /^\s*MAINTAINERS\s*\|/) {
+			$reported_maintainer_file = 1;
+		}
+
 # Check for added, moved or deleted files
 		if (!$reported_maintainer_file && !$in_commit_log &&
 		    ($line =~ /^(?:new|deleted) file mode\s*\d+\s*$/ ||