Move nfsrv_setacl() from sys/fs/nfs (the common module) to sys/fs/nfsserver
(the nfsd module) since it is only called from the server.
This is needed, since it now calls nfsrv_dssetacl(), which is in the server.
Found during "make universe" for kernels that have "options NFSCL", but not
"options NFSD".