Add new assert() statements in an attempt to help static analyzers avoid

false-positives.

FossilOrigin-Name: 9e66458592d40fbd96ea5f21339573110ca1cfe328238a020c9420a87d35dd72

src/fkey.c

@@ -1332,6 +1332,7 @@ static Trigger *fkActionTrigger(
       return 0;
     }
     assert( pStep!=0 );
+    assert( pTrigger!=0 );
 
     switch( action ){
       case OE_Restrict: