x86/vvmx: add vmcs id check into vmptrld emulation

x86/vvmx: add vmcs id check into vmptrld emulation

If a guest will do vmptrld with an incorrect vmcs id:

(XEN) Xen BUG at .../git/upstream/xen/xen/include/asm/hvm/vmx/vmx.h:333
(XEN) ----[ Xen-4.9-unstable  x86_64  debug=y   Tainted:    H ]----
(XEN) Xen call trace:
(XEN)    [<ffff82d0801f925e>] vmcs.c#arch/x86/hvm/vmx/vmcs.o.unlikely+0x28/0x19a
(XEN)    [<ffff82d0801f602c>] virtual_vmcs_vmread+0x11/0x2c
(XEN)    [<ffff82d0802002cc>] vvmx.c#_map_io_bitmap+0x86/0x88
(XEN)    [<ffff82d080202399>] nvmx_handle_vmptrld+0xf0/0x1fb
(XEN)    [<ffff82d0801fe93c>] vmx_vmexit_handler+0x132b/0x1c49
(XEN)    [<ffff82d080203e6c>] vmx_asm_vmexit_handler+0x3c/0x120

Fix this by adding appropriate checks for vmcs id during vmptrld
emulation.

Signed-off-by: Sergey Dyasli <sergey.dyasli@citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Kevin Tian <kevin.tian@intel.com>