s390/kvm: get rid of duplicate instruction

After
commit 5e8010cb
    s390: replace TIF_SIE with PF_VCPU
there is no need to load the thread info before sie_loop where
it is also loaded.
Get rid of this duplicate instruction.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>