branches/zip: btr_cur_search_to_nth_level(): Remove a duplicate check

for (rw_latch != RW_NO_LATCH) around debug code.

btr/btr0cur.c

@@ -493,17 +493,16 @@ retry_page_get:
 		}
 
 		page = buf_block_get_frame(block);
-#ifdef UNIV_ZIP_DEBUG
+
+		block->check_index_page_at_flush = TRUE;
+
 		if (rw_latch != RW_NO_LATCH) {
+#ifdef UNIV_ZIP_DEBUG
 			const page_zip_des_t*	page_zip
 				= buf_block_get_page_zip(block);
 			ut_a(!page_zip || page_zip_validate(page_zip, page));
-		}
 #endif /* UNIV_ZIP_DEBUG */
 
-		block->check_index_page_at_flush = TRUE;
-
-		if (rw_latch != RW_NO_LATCH) {
 			buf_block_dbg_add_level(block, SYNC_TREE_NODE);
 		}