Workaround for copy_file_range spuriously returning EOPNOTSUPP when attemted on a...

Workaround for copy_file_range spuriously returning EOPNOTSUPP when attemted on a NFS mount under RHEL/CentOS 7.

The syscall is supposed to return ENOSYS in most cases but when calling it on NFS it may leak through
EOPNOTSUPP even though that's supposed to be handled by the kernel and not returned to userspace.
Since it returns ENOSYS in some cases anyway this will trip the  HAS_COPY_FILE_RANGE
detection anyway, so treat EOPNOTSUPP as if it were a ENOSYS.

https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html/7.8_release_notes/deprecated_functionality#the_literal_copy_file_range_literal_call_has_been_disabled_on_local_file_systems_and_in_nfs
https://bugzilla.redhat.com/show_bug.cgi?id=1783554