remove confusing DPMS comment

FRIGN on hackers@suckless.org:
What has been bugging me for quite a while is this DPMS comment that was added
there for no reason. Every sane mind would agree that fiddling with DPMS makes
no sense whatsoever. When I slock, my screen turns off after 10 minutes. So, if
I don't like that, I disable DPMS. If I do, I just fiddle around with my mouse a
bit and get the slock promt.

slock.c

@@ -137,10 +137,6 @@ readpw(Display *dpy, struct xrandr *rr, struct lock **locks, int nscreens,
 	running = 1;
 	failure = 0;
 
-	/* As "slock" stands for "Simple X display locker", the DPMS settings
-	 * had been removed and you can set it with "xset" or some other
-	 * utility. This way the user can easily set a customized DPMS
-	 * timeout. */
 	while (running && !XNextEvent(dpy, &ev)) {
 		if (ev.type == KeyPress) {
 			explicit_bzero(&buf, sizeof(buf));