KVM: arm64: free kvm->arch.nested_mmus with kvfree()

kvm->arch.nested_mmus is allocated with kvrealloc(), hence free it with
kvfree() instead of kfree().

Fixes: 4f128f8e ("KVM: arm64: nv: Support multiple nested Stage-2 mmu structures")
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240723142204.758796-1-dakr@kernel.org


Signed-off-by: Oliver Upton <oliver.upton@linux.dev>