lib/cmdline.c: remove meaningless comment

One line of code was commented out by c++ style comment for debugging, but
forgot removing it.

Clean it up.

Link: http://lkml.kernel.org/r/1503312113-11843-1-git-send-email-bhe@redhat.com
Signed-off-by: Baoquan He <bhe@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib/cmdline.c

@@ -244,5 +244,4 @@ char *next_arg(char *args, char **param, char **val)
 
 	/* Chew up trailing spaces. */
 	return skip_spaces(next);
-	//return next;
 }