KVM: sparse fixes for kvm/x86.c

In two case statements, use the ever popular 'i' instead of index:
arch/x86/kvm/x86.c:1063:7: warning: symbol 'index' shadows an earlier one
arch/x86/kvm/x86.c:1000:9: originally declared here
arch/x86/kvm/x86.c:1079:7: warning: symbol 'index' shadows an earlier one
arch/x86/kvm/x86.c:1000:9: originally declared here

Make it static.
arch/x86/kvm/x86.c:1945:24: warning: symbol 'emulate_ops' was not declared. Should it be static?

Drop the return statements.
arch/x86/kvm/x86.c:2878:2: warning: returning void-valued expression
arch/x86/kvm/x86.c:2944:2: warning: returning void-valued expression

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>