Ensure RandR resource types are registered before resources are created.

Now that resources can be created during server initialization, make sure
the crtc, output and mode resource types are created before attempting to
create associated resources.
(cherry picked from commit ec83d67416)

randr/rrcrtc.c

@@ -55,6 +55,8 @@ RRCrtcCreate (void	*devPrivate)
 {
     RRCrtcPtr	crtc;
     
+    if (!RRInit())
+	return NULL;
     crtc = xalloc (sizeof (RRCrtcRec));
     if (!crtc)
 	return NULL;

randr/rrmode.c

@@ -67,6 +67,9 @@ RRModeGet (xRRModeInfo	*modeInfo,
 	}
     }
 
+    if (!RRInit ())
+	return NULL;
+
     mode = xalloc (sizeof (RRModeRec) + modeInfo->nameLength + 1);
     if (!mode)
 	return NULL;

randr/rroutput.c

@@ -51,6 +51,8 @@ RROutputCreate (const char  *name,
 {
     RROutputPtr	output;
 
+    if (!RRInit())
+	return NULL;
     output = xalloc (sizeof (RROutputRec) + nameLength + 1);
     if (!output)
 	return NULL;