MAINTAINERS: add zswap and zbud maintainer

Add maintainer information for zswap and zbud into the MAINTAINERS file.

Change-Id: I039bd60c230adf266aac9635aa268b974b7faf81
Signed-off-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Git-commit: 0cf31ec10e92253e2908cd830145a71043740d77
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git


Signed-off-by: Venkat Gopalakrishnan <venkatg@codeaurora.org>