i965: Dump validation list on INTEL_DEBUG=bat,submit.

This is really useful when debugging any sort of buffer management
issues, so just printing it during INTEL_DEBUG=bat,submit seems
reasonable.  With bat, we're already spamming so much output that
it doesn't really hurt.  With submit, it's still easy to grep for
the older information, and the new information is nice too.

Reviewed-by: Scott D Phillips <scott.d.phillips@intel.com>

src/mesa/drivers/dri/i965/intel_batchbuffer.c

@@ -55,7 +55,7 @@
 static void
 intel_batchbuffer_reset(struct brw_context *brw);
 
-UNUSED static void
+static void
 dump_validation_list(struct intel_batchbuffer *batch)
 {
    fprintf(stderr, "Validation list (length %d):\n", batch->exec_count);
@@ -880,6 +880,8 @@ _intel_batchbuffer_flush_fence(struct brw_context *brw,
               (float) brw->batch.aperture_space / (1024 * 1024),
               brw->batch.batch_relocs.reloc_count,
               brw->batch.state_relocs.reloc_count);
+
+      dump_validation_list(&brw->batch);
    }
 
    ret = submit_batch(brw, in_fence_fd, out_fence_fd);