sunrpc: move p_count out of struct rpc_procinfo

p_count is the only writeable memeber of struct rpc_procinfo, which is
a good candidate to be const-ified as it contains function pointers.

This patch moves it into out out struct rpc_procinfo, and into a
separate writable array that is pointed to by struct rpc_version and
indexed by p_statidx.

Signed-off-by: Christoph Hellwig <hch@lst.de>
diff --git a/fs/nfs/nfs2xdr.c b/fs/nfs/nfs2xdr.c
index a299648..16b4526 100644
--- a/fs/nfs/nfs2xdr.c
+++ b/fs/nfs/nfs2xdr.c
@@ -1170,8 +1170,10 @@ struct rpc_procinfo	nfs_procedures[] = {
 	PROC(STATFS,	fhandle,	statfsres,	0),
 };
 
+static unsigned int nfs_version2_counts[ARRAY_SIZE(nfs_procedures)];
 const struct rpc_version nfs_version2 = {
 	.number			= 2,
 	.nrprocs		= ARRAY_SIZE(nfs_procedures),
-	.procs			= nfs_procedures
+	.procs			= nfs_procedures,
+	.counts			= nfs_version2_counts,
 };