MAINTAINERS: update Ross Zwisler's email address

Redirect email to my @kernel.org account.

Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
diff --git a/.mailmap b/.mailmap
index 29ddeb1..fddb8c5 100644
--- a/.mailmap
+++ b/.mailmap
@@ -154,6 +154,7 @@
 Randy Dunlap <rdunlap@infradead.org> <rdunlap@xenotime.net>
 Rémi Denis-Courmont <rdenis@simphalempin.com>
 Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
+Ross Zwisler <zwisler@kernel.org> <ross.zwisler@linux.intel.com>
 Rudolf Marek <R.Marek@sh.cvut.cz>
 Rui Saraiva <rmps@joel.ist.utl.pt>
 Sachin P Sant <ssant@in.ibm.com>