wlags49_h2: Don't use create_proc_read_entry()

Don't use create_proc_read_entry() as that is deprecated, but rather use
proc_create_data() and seq_file instead.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Henk de Groot <pe1dnn@amsat.org>
cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
cc: linux-wireless@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>