[patch] checkpatch.pl: discourage pointless changes

[Dan Carpenter <error27@gmail.com>]

This adds a message when people use the --file option to checkpatch.pl:

NOTE: Checkpatch is a only a tool.
      Only send patches which make the code unambiguously more readable.
      Don't waste maintainer time.

Most people use checkpatch.pl to check patches which they have written,
but newbies use it with the --file option to find things to change.
>From the newbie perspective, we wrote checkpatch.pl so we should 
obviously be happy to fix all the errors it reports.  But actually 
maitainers get cranky and that makes the newbies sad and everyone has
a bad day.

The message is quite blunt, but probably if people's feelings are hurt
by a print from a script that means they are taking the script too
seriously.

Signed-off-by: Dan Carpenter <error27@gmail.com>

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index e3c7fc0..36f95c1 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -2937,6 +2937,13 @@ sub process {
 		}
 	}
 
+	if ($file && $clean == 0 && $quiet == 0) {
+		print "NOTE: Checkpatch is a only a tool.\n";
+		print "      Only send patches which make the code unambiguously more readable.\n";
+		print "      Don't waste maintainer time.\n";
+		print "\n";
+	}
+
 	if ($clean == 1 && $quiet == 0) {
 		print "$vname has no obvious style problems and is ready for submission.\n"
 	}