cris: fix the prototype of sync_serial_ioctl()

Fix:

  arch/cris/arch-v10/drivers/sync_serial.c:961: error: conflicting types for 'sync_serial_ioctl'
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/cris/arch-v10/drivers/sync_serial.c

@@ -158,7 +158,7 @@ static int sync_serial_open(struct inode *inode, struct file *file);
 static int sync_serial_release(struct inode *inode, struct file *file);
 static unsigned int sync_serial_poll(struct file *filp, poll_table *wait);
 
-static int sync_serial_ioctl(struct file *file,
+static long sync_serial_ioctl(struct file *file,
 	unsigned int cmd, unsigned long arg);
 static ssize_t sync_serial_write(struct file *file, const char *buf,
 	size_t count, loff_t *ppos);