unchecked return value returned by _lwt_CheckEdgeCrossing()

[esseffe]

_lwt_CheckEdgeCrossing() is called twice within the lwgeom_topo.c source (near lines 766 and 2144), and in both cases its return value is systematically ignored.

a more robust implementation should always test the return value then immediately returning an error when this function identifies a topology inconsistency, something like this:

   if ( ! skipISOChecks )
-   _lwt_CheckEdgeCrossing( topo, startNode, endNode, geom );
+ {
+    if (_lwt_CheckEdgeCrossing( topo, startNode, endNode, geom ) < 0)
+        return -1;
+ }

[strk]

Thanks, fixed by r13876