build: cleanup src/server directory

Change-Id: I6410df28c5999f5cbee2d3bcaa02469a29ea4c15
Signed-off-by: Spencer Oliver <spen@spen-soft.co.uk>
Reviewed-on: http://openocd.zylin.com/412
Tested-by: jenkins

src/server/server_stubs.c

@@ -24,9 +24,9 @@
 
 void openocd_sleep_prelude(void)
 {
-	// no-op
+	/* no-op */
 }
 void openocd_sleep_postlude(void)
 {
-	// no-op
+	/* no-op */
 }