KVM: PPC: e500: Less function calls in kvm_vcpu_ioctl_config_tlb() after error detection

The kfree() function was called in two cases by the
kvm_vcpu_ioctl_config_tlb() function during error handling
even if the passed data structure element contained a null pointer.

* Split a condition check for memory allocation failures.

* Adjust jump targets according to the Linux coding style convention.

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