KVM: s390: drop use of spin lock in __floating_irq_kick
It is not required to take to a lock to protect access to the cpuflags
of the local interrupt structure of a vcpu as the performed operation
is an atomic_or.
Signed-off-by: Michael Mueller <mimu@linux.vnet.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>