KVM: VMX: Fold __vmx_vcpu_run() into vmx_vcpu_run()

cea15c2 ("KVM: Move KVM context switch into own function") split vmx_vcpu_run()
to prevent multiple copies of the context switch from being generated (causing
problems due to a label).  This patch folds them back together again and adds
the __noclone attribute to prevent the label from being duplicated.

Signed-off-by: Avi Kivity <avi@redhat.com>