add proper function prototypes for Xprint/ps/PsCache.c to Xprint/ps/Ps.h

Xprint/ps/Ps.h

@@ -356,6 +356,14 @@ extern Bool InitializePsDriver(int ndx, ScreenPtr pScreen, int argc,
     char **argv);
 extern XpContextPtr PsGetContextFromWindow(WindowPtr win);
 
+/*
+ *  Functions in PsCache.c
+ */
+
+extern int PsBmIsImageCached(int gWidth, int gHeight, char *pBuffer);
+extern int PsBmPutImageInCache(int gWidth, int gHeight, char *pBuffer);
+extern void PsBmClearImageCache(void);
+
 /*
  *  Functions in PsPrint.c
  */

Xprint/ps/PsCache.c

@@ -317,7 +317,7 @@ PsBmClearImageCacheList(
 }
 
 void
-PsBmClearImageCache()
+PsBmClearImageCache(void)
 {
    PsBmClearImageCacheList(bm_cache);