KVM: VMX: fix the writing POSTED_INTR_NV

KVM: VMX: fix the writing POSTED_INTR_NV

POSTED_INTR_NV is 16bit, should not use 64bit write function

[ 5311.676074] vmwrite error: reg 3 value 0 (err 12)
  [ 5311.680001] CPU: 49 PID: 4240 Comm: qemu-system-i38 Tainted: G I 4.1.13-WR8.0.0.0_standard #1
  [ 5311.689343] Hardware name: Intel Corporation S2600WT2/S2600WT2, BIOS SE5C610.86B.01.01.0008.021120151325 02/11/2015
  [ 5311.699550] 00000000 00000000 e69a7e1c c1950de1 00000000 e69a7e38 fafcff45 fafebd24
  [ 5311.706924] 00000003 00000000 0000000c b6a06dfa e69a7e40 fafcff79 e69a7eb0 fafd5f57
  [ 5311.714296] e69a7ec0 c1080600 00000000 00000001 c0e18018 000001be 00000000 00000b43
  [ 5311.721651] Call Trace:
  [ 5311.722942] [<c1950de1>] dump_stack+0x4b/0x75
  [ 5311.726467] [<fafcff45>] vmwrite_error+0x35/0x40 [kvm_intel]
  [ 5311.731444] [<fafcff79>] vmcs_writel+0x29/0x30 [kvm_intel]
  [ 5311.736228] [<fafd5f57>] vmx_create_vcpu+0x337/0xb90 [kvm_intel]
  [ 5311.741600] [<c1080600>] ? dequeue_task_fair+0x2e0/0xf60
  [ 5311.746197] [<faf3b9ca>] kvm_arch_vcpu_create+0x3a/0x70 [kvm]
  [ 5311.751278] [<faf29e9d>] kvm_vm_ioctl+0x14d/0x640 [kvm]
  [ 5311.755771] [<c1129d44>] ? free_pages_prepare+0x1a4/0x2d0
  [ 5311.760455] [<c13e2842>] ? debug_smp_processor_id+0x12/0x20
  [ 5311.765333] [<c10793be>] ? sched_move_task+0xbe/0x170
  [ 5311.769621] [<c11752b3>] ? kmem_cache_free+0x213/0x230
  [ 5311.774016] [<faf29d50>] ? kvm_set_memory_region+0x60/0x60 [kvm]
  [ 5311.779379] [<c1199fa2>] do_vfs_ioctl+0x2e2/0x500
  [ 5311.783285] [<c11752b3>] ? kmem_cache_free+0x213/0x230
  [ 5311.787677] [<c104dc73>] ? __mmdrop+0x63/0xd0
  [ 5311.791196] [<c104dc73>] ? __mmdrop+0x63/0xd0
  [ 5311.794712] [<c104dc73>] ? __mmdrop+0x63/0xd0
  [ 5311.798234] [<c11a2ed7>] ? __fget+0x57/0x90
  [ 5311.801559] [<c11a2f72>] ? __fget_light+0x22/0x50
  [ 5311.805464] [<c119a240>] SyS_ioctl+0x80/0x90
  [ 5311.808885] [<c1957d30>] sysenter_do_call+0x12/0x12
  [ 5312.059280] kvm: zapping shadow pages for mmio generation wraparound
  [ 5313.678415] kvm [4231]: vcpu0 disabled perfctr wrmsr: 0xc2 data 0xffff
  [ 5313.726518] kvm [4231]: vcpu0 unhandled rdmsr: 0x570

Signed-off-by: Li RongQing <roy.qing.li@gmail.com>
Cc: Yang Zhang <yang.z.zhang@Intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>