documentation: Update reference, kerneltrap.org no longer works
authorPranith Kumar <bobby.prani@gmail.com>
Mon, 9 Jun 2014 15:51:23 +0000 (11:51 -0400)
committerPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Tue, 8 Jul 2014 15:14:09 +0000 (08:14 -0700)
The kerneltrap.org site no longer works, so this commit updates it to
a working reference, namely gmane.

Signed-off-by: Pranith Kumar <bobby.prani@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Documentation/RCU/RTFP.txt

Simple merge