randr: unexport and document RRProviderInitErrorValue()

Not used by any external drivers, so no need to keep it exported.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>

randr/randrstr.h

@@ -674,8 +674,6 @@ RRConfigureOutputProperty(RROutputPtr output, Atom property,
 
 /* rrprovider.c */
 #define PRIME_SYNC_PROP         "PRIME Synchronization"
-extern _X_EXPORT void
-RRProviderInitErrorValue(void);
 
 extern _X_EXPORT RRProviderPtr
 RRProviderCreate(ScreenPtr pScreen, const char *name,

randr/randrstr_priv.h

@@ -385,4 +385,9 @@ void RRDeleteAllOutputProperties(RROutputPtr output);
  */
 Bool RRProviderInit(void);
 
+/*
+ * Initialize RR provider error values
+ */
+void RRProviderInitErrorValue(void);
+
 #endif /* _XSERVER_RANDRSTR_PRIV_H_ */