KVM: VMX: Report up-to-date exit qualification to userspace

Use vmx_get_exit_qual() to read the exit qualification.

vcpu->arch.exit_qualification is cached for EPT violation only and even
for EPT violation, it is stale at this point because the up-to-date
value is cached later in handle_ept_violation().

Fixes: 70bcd708

 ("KVM: vmx: expose more information for KVM_INTERNAL_ERROR_DELIVERY_EV exits")
Signed-off-by: Chao Gao <chao.gao@intel.com>
Link: https://lore.kernel.org/r/20231229022652.300095-1-chao.gao@intel.com
Signed-off-by: Sean Christopherson <seanjc@google.com>