increase and decrese resource tool has methods with multiple consecutive returns

(Found by utils/create_cppcheck_report)

src/editor/tools/editor_decrease_resources_tool.cc:95 and src/editor/tools/editor_increase_resources_tool.cc:138 both have two consecutive return statements. The easiest fix would be to remove the second one "return 0;", but as I don't know the code, I am not sure what the intended behaviour is here.