PR 9871 (partial) fix. Removed more embedded-C in nfs_proc.stp and nfs.stp.

PR 9871 (partial) fix.  Removed more embedded-C in nfs_proc.stp and nfs.stp.

* tapset/nfs_proc.stp: Added script functions NFS_I(), NFS_FH(),
  NFS_SERVER, NFS_PROTO.  Rewrote embedded-C functions __nfsv4_bitmask()
  and __getfh_inode() in script language.
* tapset/nfs.stp: Rewrote embedded-C functions __nfsi_cache_valid(),
  __nfsi_rcache_time(), __nfsi_attr_time(), __nfsi_ndirty(),
  __nfs_server_rsize(), __nfs_version(), __nfs_server_wsize(),
  __nfs_rpages(), and __nfs_wpages() in script language.