MDEV-33855 MSAN use-of-uninitialized-value in rtr_pcur_getnext_from_path()

rtr_pcur_getnext_from_path(): Remove a bogus assertion
that may cause a data races with buf_LRU_block_free_non_file_page().

If my_latch_mode == BTR_MODIFY_LEAF, we would have released all page
latches and buffer-fixes by invoking mtr->rollback_to_savepoint(1).
After this point, the btr_cur->page_cur.block is no longer valid and
must not be accessed.

Before 03ca6495 this assertion had
been disabled, because the preprocessor symbol UNIV_RTR_DEBUG
had never been enabled (except when explicitly specified in
CMAKE_CXX_FLAGS).

Reviewed by: Debarun Banerjee

storage/innobase/gis/gis0sea.cc

@@ -289,10 +289,6 @@ rtr_pcur_getnext_from_path(
 			mtr->rollback_to_savepoint(1);
 		}
 
-		ut_ad((my_latch_mode | 4) == BTR_CONT_MODIFY_TREE
-		      || !page_is_leaf(btr_cur_get_page(btr_cur))
-		      || !btr_cur->page_cur.block->page.lock.have_any());
-
 		const auto block_savepoint = mtr->get_savepoint();
 		block = buf_page_get_gen(
 			page_id_t(index->table->space_id,