Fix dialyzer warnings

Author: Mark Allen

src/lager_app.erl

@@ -188,7 +188,7 @@ configure_sink(Sink, SinkDef) ->
     determine_async_behavior(Sink, proplists:get_value(async_threshold, SinkDef),
                              proplists:get_value(async_threshold_window, SinkDef)
                             ),
-    maybe_install_sink_killer(Sink, proplists:get_value(killer_hwm, SinkDef), 
+    _ = maybe_install_sink_killer(Sink, proplists:get_value(killer_hwm, SinkDef), 
                               proplists:get_value(killer_reinstall_after, SinkDef)),
     start_handlers(Sink,
                    proplists:get_value(handlers, SinkDef, [])),
@@ -226,7 +226,7 @@ boot() ->
                              get_env(lager, async_threshold),
                              get_env(lager, async_threshold_window)),
 
-    maybe_install_sink_killer(?DEFAULT_SINK, get_env(lager, killer_hwm), 
+    _ = maybe_install_sink_killer(?DEFAULT_SINK, get_env(lager, killer_hwm), 
                               get_env(lager, killer_reinstall_after)),
 
     start_handlers(?DEFAULT_SINK,

src/lager_handler_watcher.erl

@@ -88,7 +88,7 @@ handle_info(reinstall_handler, #state{module=Module, config=Config, sink=Sink} =
     install_handler(Sink, Module, Config),
     {noreply, State};
 handle_info({reboot, Sink}, State) ->
-    lager_app:boot(Sink),
+    _ = lager_app:boot(Sink),
     {noreply, State};
 handle_info(stop, State) ->
     {stop, normal, State};