qemu security update

[15:3.0.0-4.el7]

• usb-mtp: use O_NOFOLLOW and O_CLOEXEC. (Gerd Hoffmann) [Orabug: 29056673] {CVE-2018-16872}
• pvrdma: add uar_read routine (Prasad J Pandit) {CVE-2018-20191}
• pvrdma: release ring object in case of an error (Prasad J Pandit) [Orabug: 29171822] {CVE-2018-20126}
• pvrdma: check number of pages when creating rings (Prasad J Pandit) [Orabug: 29171821] {CVE-2018-20125}
• pvrdma: check return value from pvrdma_idx_ring_has_ routines (Prasad J Pandit) [Orabug: 29171820] {CVE-2018-20216}
• rdma: remove unused VENDOR_ERR_NO_SGE macro (Prasad J Pandit) [Orabug: 29121181] {CVE-2018-20124}
• rdma: check num_sge does not exceed MAX_SGE (Prasad J Pandit) [Orabug: 29121181] {CVE-2018-20124}
• i386: Add ‘stibp’ flag name (Eduardo Habkost) [Orabug: 29114828]
• i386: Add some MSR based features on Cascadelake-Server CPU model (Tao Xu) [Orabug: 29029615]
• i386: Update stepping of Cascadelake-Server (Tao Xu) [Orabug: 29029615]
• kvm: Use KVM_GET_MSR_INDEX_LIST for MSR_IA32_ARCH_CAPABILITIES support (Bandan Das) [Orabug: 29029615]
• x86: define a new MSR based feature word – FEATURE_WORDS_ARCH_CAPABILITIES (Robert Hoo) [Orabug: 29029615]
• x86: Data structure changes to support MSR based features (Robert Hoo) [Orabug: 29029615]
• kvm: Add support to KVM_GET_MSR_FEATURE_INDEX_LIST and KVM_GET_MSRS system ioctl (Robert Hoo) [Orabug: 29029615]
• i386: Add CPUID bit and feature words for IA32_ARCH_CAPABILITIES MSR (Robert Hoo) [Orabug: 29029615]
• i386: Add new MSR indices for IA32_PRED_CMD and IA32_ARCH_CAPABILITIES (Robert Hoo) [Orabug: 29029615]
• Fix compilation issue: ‘qapi_event_send_failover_primary_changed’ not declared (Mark Kanda) [Orabug: 29121163]
• lsi_scsi: add support for PPR Extended Message (George Kennedy) [Orabug: 28879117]