ptp: fix error print of ptp_kvm on X86_64 platform

Commit a86ed2cf ("ptp: Don't print an error if ptp_kvm is not supported")
fixes the error message print on ARM platform by only concerning about
the case that the error returned from kvm_arch_ptp_init() is not -EOPNOTSUPP.
Although the ARM platform returns -EOPNOTSUPP if ptp_kvm is not supported
while X86_64 platform returns -KVM_EOPNOTSUPP, both error codes share the
same value 95.

Actually kvm_arch_ptp_init() on X86_64 platform can return three kinds of
errors (-KVM_ENOSYS, -KVM_EOPNOTSUPP and -KVM_EFAULT). The problem is that
-KVM_EOPNOTSUPP is masked out and -KVM_EFAULT is ignored among them.
This patch fixes this by returning them to ptp_kvm_init() respectively.

Signed-off-by: Kele Huang <huangkele@bytedance.com>
Signed-off-by: David S. Miller <davem@davemloft.net>