gallium/postprocessing: fix shader parsing

tokens was converted to a pointer, which made the Elements macro return 1.

Broken by e87fc11cac.

Cc: mesa-stable@lists.freedesktop.org
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Brian Paul <brianp@vmware.com>

src/gallium/auxiliary/postprocess/pp_run.c

@@ -218,8 +218,8 @@ pp_tgsi_to_state(struct pipe_context *pipe, const char *text, bool isvs,
       return NULL;
    }
 
-   if (tgsi_text_translate(text, tokens, Elements(tokens)) == FALSE) {
-      pp_debug("Failed to translate %s\n", name);
+   if (tgsi_text_translate(text, tokens, PP_MAX_TOKENS) == FALSE) {
+      _debug_printf("pp: Failed to translate a shader for %s\n", name);
       return NULL;
    }