tty: tty_jobctrl: Fix 2 incorrectly documented functions

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

drivers/tty/tty_jobctrl.c:33: warning: expecting prototype for tty_check_change(). Prototype was for __tty_check_change() instead
drivers/tty/tty_jobctrl.c:97: warning: expecting prototype for proc_set_tty(). Prototype was for __proc_set_tty() instead

Cc: Greg Kroah-Hartman <[e-mail]>
Cc: Jiri Slaby <[e-mail]>
Signed-off-by: Lee Jones <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/tty/tty_jobctrl.c

···
 }
 
 /**
- *	tty_check_change	-	check for POSIX terminal changes
+ *	__tty_check_change	-	check for POSIX terminal changes
  *	@tty: tty to check
  *	@sig: signal to send
  *
···
 }
 
 /**
- * proc_set_tty -  set the controlling terminal
+ * __proc_set_tty -  set the controlling terminal
  *	@tty: tty structure
  *
  * Only callable by the session leader and only if it does not already have