avoid construction followed by assignment

Author: Daniel Kroening

jbmc/src/java_bytecode/remove_instanceof.cpp

@@ -210,8 +210,7 @@ bool remove_instanceoft::lower_instanceof(
     // If this is a branch target, add a skip beforehand so we can splice new
     // GOTO programs before the target instruction without inserting into the
     // wrong basic block.
-    goto_program.insert_before_swap(target);
-    *target = goto_programt::make_skip();
+    goto_program.insert_before_swap(target, goto_programt::make_skip());
     // Actually alter the now-moved instruction:
     ++target;
   }