declare buf only if XINERAMA support is used

config.mk

@@ -11,8 +11,8 @@ X11INC = /usr/X11R6/include
 X11LIB = /usr/X11R6/lib
 
 # Xinerama, un-comment if you want it
-XINERAMALIBS = -L${X11LIB} -lXinerama
+#XINERAMALIBS = -L${X11LIB} -lXinerama
-XINERAMAFLAGS = -DXINERAMA
+#XINERAMAFLAGS = -DXINERAMA
 
 # includes and libs
 INCS = -I. -I/usr/include -I${X11INC}

dwm.c

@@ -599,7 +599,6 @@ die(const char *errstr, ...) {
 
 void
 drawbar(Monitor *m) {
-	char buf[2];
 	int x;
 	unsigned int i, occ = 0, urg = 0;
 	unsigned long *col;
@@ -616,6 +615,7 @@ drawbar(Monitor *m) {
 	dc.x = 0;
 #ifdef XINERAMA
 	{
+		char buf[2];
 		buf[0] = m->screen_number + '0';
 		buf[1] = '\0';
 		dc.w = TEXTW(buf);