remove obsolete references to powertweak

This tool hasn't been maintained in over a decade, and is pretty much
useless these days.  Let's pretend it never happened.

Also remove a long-dead email address.

Signed-off-by: Dave Jones <davej@fedoraproject.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/affs/Changes b/fs/affs/Changes
index a29409c..b41c2c9 100644
--- a/fs/affs/Changes
+++ b/fs/affs/Changes
@@ -91,7 +91,7 @@
 Version 3.11
 ------------
 
-- Converted to use 2.3.x page cache [Dave Jones <dave@powertweak.com>]
+- Converted to use 2.3.x page cache [Dave Jones]
 - Corruption in truncate() bugfix [Ken Tyler <kent@werple.net.au>]
 
 Version 3.10