cygserver: Speed up non-debug scenario

_log/_vlog were always called so we always had a function call hit even
if we're not debugging.  Expand on the debugging macros so the decision
to call _log/_vlog is done in the caller already.  Also, make a log level
difference between syscall_printf and system_printf.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>

winsup/cygserver/sysv_msg.cc

@@ -52,7 +52,7 @@ __FBSDID("$FreeBSD: /usr/local/www/cvsroot/FreeBSD/src/sys/kern/sysv_msg.c,v 1.5
 #endif /* __CYGWIN__ */
 
 #ifdef MSG_DEBUG
-#define DPRINTF(a)	debug_printf a
+#define DPRINTF(a)	debug a
 #else
 #define DPRINTF(a)
 #endif