drivers/tty/tty_jobctrl.c - fix non-kerneldoc comment

Building with W=1 reports (among other things):
  CC      drivers/tty/tty_jobctrl.o
drivers/tty/tty_jobctrl.c:317: warning: Cannot understand  *
 on line 317 - I thought it was a doc line

Fix up the non-kerneldoc comment. (other warnings to be cleaned up in separate patch)

Signed-off-by Valdis Kletnieks <valdis.kletnieks@vt.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>