Using C++ style block comment in c-mode

[Maindoor]

I already had this in my .emacs file for c mode. So I added
a set variable to support c++ style comments for C, see at
the end. But it still doesn't work. any suggestions ?

(setq c-default-style "linux-c-mode")
(defun linux-c-mode ()
  (interactive)
  (c-mode)
  (setq c-indent-level 8)
  (setq c-brace-imaginary-offset 0)
  (setq c-brace-offset -8)
  (setq c-argdecl-indent 8)
  (setq c-label-offset -8)
  (setq c-continued-statement-offset 8)
  (setq indent-tabs-mode nil)
  (setq tab-width 4)
->  (setq comment-start "// ")
->  (setq comment-end " "))

Regards,
Maindoor.