displaylib: display driver lower case by default (cosmetics)

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@63468 15284696-431f-4ddb-bdfa-cd5b030d7da7

lib/display/r_raster.c

@@ -140,9 +140,9 @@ int D_open_driver(void)
     }
     
     const struct driver *drv =
-	(p && G_strcasecmp(p, "PNG")   == 0) ? PNG_Driver() :
-	(p && G_strcasecmp(p, "PS")    == 0) ? PS_Driver() :
-	(p && G_strcasecmp(p, "HTML")  == 0) ? HTML_Driver() :
+	(p && G_strcasecmp(p, "png")   == 0) ? PNG_Driver() :
+	(p && G_strcasecmp(p, "ps")    == 0) ? PS_Driver() :
+	(p && G_strcasecmp(p, "html")  == 0) ? HTML_Driver() :
 #ifdef USE_CAIRO
 	(p && G_strcasecmp(p, "cairo") == 0) ? Cairo_Driver() :
 	Cairo_Driver();