MAINTAINERS: remove Radim from KVM maintainers

Radim's kernel.org email is bouncing, which I take as a signal that
he is not really able to deal with KVM at this time.  Make MAINTAINERS
match the effective value of KVM's bus factor.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

MAINTAINERS

@@ -8927,7 +8927,6 @@ F:	include/linux/umh.h
 KERNEL VIRTUAL MACHINE (KVM)
 M:	Paolo Bonzini <pbonzini@redhat.com>
-M:	Radim Krčmář <rkrcmar@redhat.com>
 L:	kvm@vger.kernel.org
 W:	http://www.linux-kvm.org
 T:	git git://git.kernel.org/pub/scm/virt/kvm/kvm.git
@@ -8999,7 +8998,6 @@ F:	tools/testing/selftests/kvm/*/s390x/
 KERNEL VIRTUAL MACHINE FOR X86 (KVM/x86)
 M:	Paolo Bonzini <pbonzini@redhat.com>
-M:	Radim Krčmář <rkrcmar@redhat.com>
 R:	Sean Christopherson <sean.j.christopherson@intel.com>
 R:	Vitaly Kuznetsov <vkuznets@redhat.com>
 R:	Wanpeng Li <wanpengli@tencent.com>