target/i386/kvm: Replace ARRAY_SIZE(msr_handlers) with KVM_MSR_FILTER_MAX_RANGES

target/i386/kvm: Replace ARRAY_SIZE(msr_handlers) with KVM_MSR_FILTER_MAX_RANGES

kvm_install_msr_filters() uses KVM_MSR_FILTER_MAX_RANGES as the bound
when traversing msr_handlers[], while other places still compute the
size by ARRAY_SIZE(msr_handlers).

In fact, msr_handlers[] is an array with the fixed size
KVM_MSR_FILTER_MAX_RANGES, and this has to be true because
kvm_install_msr_filters copies from one array to the other.
For code consistency, assert that they match and use
ARRAY_SIZE(msr_handlers) everywehere.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>