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/affs/super.c

@@ -135,7 +135,7 @@ enum {
 	Opt_verbose, Opt_volume, Opt_ignore, Opt_err,
 };
 
-static match_table_t tokens = {
+static const match_table_t tokens = {
 	{Opt_bs, "bs=%u"},
 	{Opt_mode, "mode=%o"},
 	{Opt_mufs, "mufs"},