tty_buffer: Fix distinct type warning

CC      drivers/char/tty_buffer.o
drivers/char/tty_buffer.c: In function ‘tty_insert_flip_string_fixed_flag’:
drivers/char/tty_buffer.c:251: warning: comparison of distinct pointer types lacks a cast
drivers/char/tty_buffer.c: In function ‘tty_insert_flip_string_flags’:
drivers/char/tty_buffer.c:288: warning: comparison of distinct pointer types lacks a cast

Fix it by replacing min() with min_t() in tty_insert_flip_string_flags and
					  tty_insert_flip_string_fixed_flag().
Signed-off-by: Fang Wenqi <antonf@turbolinux.com.cn>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/char/tty_buffer.c

@@ -248,7 +248,7 @@ int tty_insert_flip_string_fixed_flag(struct tty_struct *tty,
 {
 	int copied = 0;
 	do {
-		int goal = min(size - copied, TTY_BUFFER_PAGE);
+		int goal = min_t(size_t, size - copied, TTY_BUFFER_PAGE);
 		int space = tty_buffer_request_room(tty, goal);
 		struct tty_buffer *tb = tty->buf.tail;
 		/* If there is no space then tb may be NULL */
@@ -285,7 +285,7 @@ int tty_insert_flip_string_flags(struct tty_struct *tty,
 {
 	int copied = 0;
 	do {
-		int goal = min(size - copied, TTY_BUFFER_PAGE);
+		int goal = min_t(size_t, size - copied, TTY_BUFFER_PAGE);
 		int space = tty_buffer_request_room(tty, goal);
 		struct tty_buffer *tb = tty->buf.tail;
 		/* If there is no space then tb may be NULL */