drivers: tty: Merge alloc_tty_struct and initialize_tty_struct

The two functions alloc_tty_struct and initialize_tty_struct are
always called together. Merge them into alloc_tty_struct, updating its
prototype and the only two callers of these functions.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --cc drivers/tty/pty.c
Simple merge

diff --cc drivers/tty/tty_io.c
Simple merge

diff --cc include/linux/tty.h
Simple merge