These macro definitions are no longer needed as the NFS OSX port is long
dead.  The vfs_statfs macro conflicts with the vfsops field of the same
name.

Submitted by:	shivank@
Reviewed by:	rmacklem
MFC after:	2 weeks
Sponsored by:	Google, Inc. (GSoC 2020)
Differential Revision:	https://reviews.freebsd.org/D25263