vfs: don't parse "silent" option

Parsing "silent" and clearing SB_SILENT makes zero sense.

Parsing "silent" and setting SB_SILENT would make a bit more sense, but
apparently nobody cares.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

fs/fs_context.c

@@ -52,7 +52,6 @@ static const struct constant_table common_clear_sb_flag[] = {
 	{ "nolazytime",	SB_LAZYTIME },
 	{ "nomand",	SB_MANDLOCK },
 	{ "rw",		SB_RDONLY },
-	{ "silent",	SB_SILENT },
 	{ },
 };