KVM: PPC: e500: Delete an unnecessary initialisation in kvm_vcpu_ioctl_config_tlb()

The local variable "g2h_bitmap" will be set to an appropriate value
a bit later. Thus omit the explicit initialisation at the beginning.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>