MAINTAINERS: Add Zack as maintainer of vmmouse driver

Zack Rusin will be taking over the maintainership of the VMware
vmmouse driver. Update the MAINTAINERS file to reflect this change.
Signed-off-by: Srivatsa S. Bhat (VMware) <srivatsa@csail.mit.edu>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Zack Rusin <zackr@vmware.com>
Link: https://lore.kernel.org/r/164574146977.654750.10918397477833459687.stgit@csail.mit.edu

MAINTAINERS

@@ -20628,6 +20628,7 @@ S:	Maintained
 F:	drivers/misc/vmw_vmci/
 
 VMWARE VMMOUSE SUBDRIVER
+M:	Zack Rusin <zackr@vmware.com>
 M:	"VMware Graphics" <linux-graphics-maintainer@vmware.com>
 M:	"VMware, Inc." <pv-drivers@vmware.com>
 L:	linux-input@vger.kernel.org