NFS: missing nfs_fattr_init in nfs3_proc_getacl and nfs3_proc_setacls (resend #2)

The fattrs used in the NFSv3 getacl/setacl calls are not being properly
initialized. This occasionally causes nfs_update_inode to fall into
NFSv4 specific codepaths when handling post-op attrs from these calls.

Thanks to Cai Qian for noticing the spurious NFSv4 messages in debug
output from a v3 mount...

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>