fix Christoph's email addresses

There are various email addresses for me throughout the kernel.  Use the
one that will always be valid.

Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/MAINTAINERS b/MAINTAINERS
index 99bd725..67d34bb 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -8473,7 +8473,7 @@
 
 PER-CPU MEMORY ALLOCATOR
 M:	Tejun Heo <tj@kernel.org>
-M:	Christoph Lameter <cl@linux-foundation.org>
+M:	Christoph Lameter <cl@linux.com>
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu.git
 S:	Maintained
 F:	include/linux/percpu*.h