vc4: Fix unused variable warning.

Fixes: bb84fa146f ("util: use C99 declaration in the for-loop hash_table_foreach() macro")

src/gallium/drivers/vc4/vc4_program.c

@@ -3031,7 +3031,6 @@ vc4_program_fini(struct pipe_context *pctx)
 {
         struct vc4_context *vc4 = vc4_context(pctx);
 
-        struct hash_entry *entry;
         hash_table_foreach(vc4->fs_cache, entry) {
                 struct vc4_compiled_shader *shader = entry->data;
                 vc4_bo_unreference(&shader->bo);