um: line, remove put_char

um's put_char only calls write. And the tty layer/disciplines do the
same if put_char is NULL.

So we can safely remove this put_char wrapper.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Link: https://lore.kernel.org/r/20200615074856.18949-1-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

arch/um/drivers/line.c

@@ -184,11 +184,6 @@ void line_flush_chars(struct tty_struct *tty)
 	line_flush_buffer(tty);
 }
 
-int line_put_char(struct tty_struct *tty, unsigned char ch)
-{
-	return line_write(tty, &ch, sizeof(ch));
-}
-
 int line_write(struct tty_struct *tty, const unsigned char *buf, int len)
 {
 	struct line *line = tty->driver_data;

arch/um/drivers/line.h

@@ -66,7 +66,6 @@ extern int line_setup(char **conf, unsigned nlines, char **def,
 		      char *init, char *name);
 extern int line_write(struct tty_struct *tty, const unsigned char *buf,
 		      int len);
-extern int line_put_char(struct tty_struct *tty, unsigned char ch);
 extern void line_set_termios(struct tty_struct *tty, struct ktermios * old);
 extern int line_chars_in_buffer(struct tty_struct *tty);
 extern void line_flush_buffer(struct tty_struct *tty);

arch/um/drivers/ssl.c

@@ -95,7 +95,6 @@ static const struct tty_operations ssl_ops = {
 	.open 	 		= line_open,
 	.close 	 		= line_close,
 	.write 	 		= line_write,
-	.put_char 		= line_put_char,
 	.write_room		= line_write_room,
 	.chars_in_buffer 	= line_chars_in_buffer,
 	.flush_buffer 		= line_flush_buffer,

arch/um/drivers/stdio_console.c

@@ -102,7 +102,6 @@ static const struct tty_operations console_ops = {
 	.install		= con_install,
 	.close 	 		= line_close,
 	.write 	 		= line_write,
-	.put_char 		= line_put_char,
 	.write_room		= line_write_room,
 	.chars_in_buffer 	= line_chars_in_buffer,
 	.flush_buffer 		= line_flush_buffer,