Remove an unnecessary mutex

Alc/ALc.c

@@ -2638,7 +2638,6 @@ static ALvoid InitContext(ALCcontext *Context)
     Context->MetersPerUnit = AL_DEFAULT_METERS_PER_UNIT;
     ATOMIC_FLAG_TEST_AND_SET(&Context->PropsClean, almemory_order_relaxed);
     ATOMIC_INIT(&Context->DeferUpdates, AL_FALSE);
-    almtx_init(&Context->EventThrdLock, almtx_plain);
     alsem_init(&Context->EventSem, 0);
     Context->AsyncEvents = NULL;
     ATOMIC_INIT(&Context->EnabledEvts, 0);
@@ -2779,7 +2778,6 @@ static void FreeContext(ALCcontext *context)
     TRACE("Freed "SZFMT" listener property object%s\n", count, (count==1)?"":"s");
 
     almtx_destroy(&context->EventCbLock);
-    almtx_destroy(&context->EventThrdLock);
     alsem_destroy(&context->EventSem);
 
     ll_ringbuffer_free(context->AsyncEvents);

OpenAL32/Include/alMain.h

@@ -827,7 +827,6 @@ struct ALCcontext_struct {
 
     ATOMIC(struct ALeffectslotArray*) ActiveAuxSlots;
 
-    almtx_t EventThrdLock;
     althrd_t EventThread;
     alsem_t EventSem;
     struct ll_ringbuffer *AsyncEvents;

OpenAL32/event.c

@@ -73,7 +73,6 @@ AL_API void AL_APIENTRY alEventControlSOFT(ALsizei count, const ALenum *types, A
             SETERR_GOTO(context, AL_INVALID_ENUM, done, "Invalid event type 0x%04x", types[i]);
     }
 
-    almtx_lock(&context->EventThrdLock);
     if(enable)
     {
         enabledevts = ATOMIC_LOAD(&context->EnabledEvts, almemory_order_relaxed);
@@ -98,7 +97,6 @@ AL_API void AL_APIENTRY alEventControlSOFT(ALsizei count, const ALenum *types, A
         almtx_lock(&context->EventCbLock);
         almtx_unlock(&context->EventCbLock);
     }
-    almtx_unlock(&context->EventThrdLock);
 
 done:
     ALCcontext_DecRef(context);