vfs: Use const for kernel parser table

This is a much better version of a previous patch to make the parser
tables constant. Rather than changing the typedef, we put the "const" in
all the various places where its required, allowing the __initconst
exception for nfsroot which was the cause of the previous trouble.

This was posted for review some time ago and I believe its been in -mm
since then.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Cc: Alexander Viro <aviro@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/nfs/super.c

@@ -98,7 +98,7 @@ enum {
 	Opt_err
 };
 
-static match_table_t nfs_mount_option_tokens = {
+static const match_table_t nfs_mount_option_tokens = {
 	{ Opt_userspace, "bg" },
 	{ Opt_userspace, "fg" },
 	{ Opt_userspace, "retry=%s" },
@@ -163,7 +163,7 @@ enum {
 	Opt_xprt_err
 };
 
-static match_table_t nfs_xprt_protocol_tokens = {
+static const match_table_t nfs_xprt_protocol_tokens = {
 	{ Opt_xprt_udp, "udp" },
 	{ Opt_xprt_tcp, "tcp" },
 	{ Opt_xprt_rdma, "rdma" },
@@ -180,7 +180,7 @@ enum {
 	Opt_sec_err
 };
 
-static match_table_t nfs_secflavor_tokens = {
+static const match_table_t nfs_secflavor_tokens = {
 	{ Opt_sec_none, "none" },
 	{ Opt_sec_none, "null" },
 	{ Opt_sec_sys, "sys" },