tty: tty_jobctrl: Add missing function parameter descriptions

Fixes the following W=1 kernel build warning(s):

 drivers/tty/tty_jobctrl.c:32: warning: Function parameter or member 'sig' not described in '__tty_check_change'
 drivers/tty/tty_jobctrl.c:95: warning: Function parameter or member 'tty' not described in '__proc_set_tty'
 drivers/tty/tty_jobctrl.c:344: warning: Function parameter or member 'file' not described in 'tiocsctty'

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20201104193549.4026187-8-lee.jones@linaro.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/tty_jobctrl.c

@@ -21,6 +21,7 @@ static int is_ignored(int sig)
 /**
  *	tty_check_change	-	check for POSIX terminal changes
  *	@tty: tty to check
+ *	@sig: signal to send
  *
  *	If we try to write to, or set the state of, a terminal and we're
  *	not in the foreground, send a SIGTTOU.  If the signal is blocked or
@@ -83,6 +84,7 @@ void proc_clear_tty(struct task_struct *p)
 
 /**
  * proc_set_tty -  set the controlling terminal
+ *	@tty: tty structure
  *
  * Only callable by the session leader and only if it does not already have
  * a controlling terminal.
@@ -330,6 +332,7 @@ void no_tty(void)
 /**
  *	tiocsctty	-	set controlling tty
  *	@tty: tty structure
+ *	@file: file structure used to check permissions
  *	@arg: user argument
  *
  *	This ioctl is used to manage job control. It permits a session