MAITAINERS: List Fam Zheng as reviewer for SCSI patches

Just so that I notice those patches more easily.
Signed-off-by: NFam Zheng <famz@redhat.com>
Message-Id: <20171205072220.885-1-famz@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

MAINTAINERS

@@ -1011,6 +1011,7 @@ T: git git://github.com/jasowang/qemu.git net
 
 SCSI
 M: Paolo Bonzini <pbonzini@redhat.com>
+R: Fam Zheng <famz@redhat.com>
 S: Supported
 F: include/hw/scsi/*
 F: hw/scsi/*
@@ -1271,6 +1272,7 @@ T: git git://github.com/stefanha/qemu.git block
 
 Block SCSI subsystem
 M: Paolo Bonzini <pbonzini@redhat.com>
+R: Fam Zheng <famz@redhat.com>
 L: qemu-block@nongnu.org
 S: Supported
 F: include/scsi/*