Remove EventLoopError::AlreadyRunning

This is already prevented by the type-system, and as such it doesn't
make sense to have an error case for this.

src/platform_impl/android/mod.rs

@@ -491,10 +491,6 @@ impl<T: 'static> EventLoop<T> {
     where
         F: FnMut(event::Event<T>, &event_loop::EventLoopWindowTarget),
     {
-        if self.loop_running {
-            return Err(EventLoopError::AlreadyRunning);
-        }
-
         loop {
             match self.pump_events(None, &mut event_handler) {
                 PumpStatus::Exit(0) => {

src/platform_impl/linux/wayland/event_loop/mod.rs

@@ -192,10 +192,6 @@ impl<T: 'static> EventLoop<T> {
     where
         F: FnMut(Event<T>, &RootEventLoopWindowTarget),
     {
-        if self.loop_running {
-            return Err(EventLoopError::AlreadyRunning);
-        }
-
         let exit = loop {
             match self.pump_events(None, &mut event_handler) {
                 PumpStatus::Exit(0) => {

src/platform_impl/linux/x11/mod.rs

@@ -402,10 +402,6 @@ impl<T: 'static> EventLoop<T> {
     where
         F: FnMut(Event<T>, &RootELW),
     {
-        if self.loop_running {
-            return Err(EventLoopError::AlreadyRunning);
-        }
-
         let exit = loop {
             match self.pump_events(None, &mut event_handler) {
                 PumpStatus::Exit(0) => {

src/platform_impl/macos/event_loop.rs

@@ -279,10 +279,6 @@ impl<T> EventLoop<T> {
     where
         F: FnMut(Event<T>, &RootWindowTarget),
     {
-        if self.delegate.is_running() {
-            return Err(EventLoopError::AlreadyRunning);
-        }
-
         let callback = map_user_event(callback, self.receiver.clone());
 
         // # Safety

src/platform_impl/windows/event_loop.rs

@@ -94,8 +94,6 @@ use crate::{
 };
 use runner::{EventLoopRunner, EventLoopRunnerShared};
 
-use self::runner::RunnerState;
-
 use super::{window::set_skip_taskbar, SelectedCursor};
 
 /// some backends like macos uses an uninhabited `Never` type,
@@ -246,9 +244,6 @@ impl<T: 'static> EventLoop<T> {
     {
         {
             let runner = &self.window_target.p.runner_shared;
-            if runner.state() != RunnerState::Uninitialized {
-                return Err(EventLoopError::AlreadyRunning);
-            }
 
             let event_loop_windows_ref = &self.window_target;
             let user_event_receiver = &self.user_event_receiver;

src/platform_impl/windows/event_loop/runner.rs

@@ -143,10 +143,6 @@ impl<T> EventLoopRunner<T> {
         }
     }
 
-    pub fn state(&self) -> RunnerState {
-        self.runner_state.get()
-    }
-
     pub fn set_control_flow(&self, control_flow: ControlFlow) {
         self.control_flow.set(control_flow)
     }