MAINTAINERS: email update

Changed to my private email address as I left Samsung.
Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@gmail.com>

MAINTAINERS

@@ -4888,7 +4888,7 @@ F:	drivers/ipack/
 
 INTEGRITY MEASUREMENT ARCHITECTURE (IMA)
 M:	Mimi Zohar <zohar@linux.vnet.ibm.com>
-M:	Dmitry Kasatkin <d.kasatkin@samsung.com>
+M:	Dmitry Kasatkin <dmitry.kasatkin@gmail.com>
 L:	linux-ima-devel@lists.sourceforge.net
 L:	linux-ima-user@lists.sourceforge.net
 L:	linux-security-module@vger.kernel.org