kvm: free resources after canceling async_pf
kvm: free resources after canceling async_pf

When we cancel 'async_pf_execute()', we should behave as if the work was
never scheduled in 'kvm_setup_async_pf()'.
Fixes a bug when we can't unload module because the vm wasn't destroyed.

Signed-off-by: Radim Krčmář <e4aea3f2c531804c57884e1d444a6744efb5af4d@redhat.com>
Reviewed-by: Paolo Bonzini <69d3ebcf5ee4e7f05a50dc23cd96655b730804b4@redhat.com>
Reviewed-by: Gleb Natapov <03189597947f75187c4136ade35aec34feed9dc1@redhat.com>
Signed-off-by: Paolo Bonzini <69d3ebcf5ee4e7f05a50dc23cd96655b730804b4@redhat.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs