SUNRPC: display human-readable procedure name in rpc_iostats output

Add fields to the rpc_procinfo struct that allow the display of a
human-readable name for each procedure in the rpc_iostats output.

Also fix it so that the NFSv4 stats are broken up correctly by
sub-procedure number.  NFSv4 uses only two real RPC procedures:
NULL, and COMPOUND.

Test plan:
Mount with NFSv2, NFSv3, and NFSv4, and do "cat /proc/self/mountstats".

Signed-off-by: Chuck Lever <cel@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/nfs2xdr.c b/fs/nfs/nfs2xdr.c
index 7fc0560..8cdc792 100644
--- a/fs/nfs/nfs2xdr.c
+++ b/fs/nfs/nfs2xdr.c
@@ -682,7 +682,9 @@
 	.p_encode   =  (kxdrproc_t) nfs_xdr_##argtype,			\
 	.p_decode   =  (kxdrproc_t) nfs_xdr_##restype,			\
 	.p_bufsiz   =  MAX(NFS_##argtype##_sz,NFS_##restype##_sz) << 2,	\
-	.p_timer    =  timer						\
+	.p_timer    =  timer,						\
+	.p_statidx  =  NFSPROC_##proc,					\
+	.p_name     =  #proc,						\
 	}
 struct rpc_procinfo	nfs_procedures[] = {
     PROC(GETATTR,	fhandle,	attrstat, 1),