nfscl: Clean up the code by removing unused arguments
The "void *stuff" (also called fstuff and dstuff) argument was used by the Mac OSX port. For FreeBSD, this argument is always NULL, so remove it to clean up the code. This commit gets rid of "stuff" for assorted functions defined in nfs_clrpcops.c and called in nfs_clvnops.c. Future commits will do the same for other functions. This commit should not result in a semantics change.