task_content: drop spurious CMD_EVENT_CORE_INIT(NULL) after subsystem init

In the PENDING_SUBSYSTEM_INIT branch, content_load fires
command_event(CMD_EVENT_CORE_INIT, NULL) immediately after a
successful retroarch_main_init. The handler at retroarch.c:4440-4448
performs three pre-init side effects before falling through to the
!type check that returns false:

  - content_reset_savestate_backups()
  - disk_control_set_ext_callback(disk_control, NULL)
  - audio_st->callback.{callback,set_state} = NULL

retroarch_main_init has already initialized the core via its own
CMD_EVENT_CORE_INIT(&type) at line 8273. The core's retro_init may
have called env(SET_DISK_CONTROL_INTERFACE, ...) and
env(SET_AUDIO_CALLBACK, ...) at that point, populating the very
callbacks this second call wipes.

Result: subsystems on cores that use disk control or audio callback
lose those interfaces immediately after content load. The actual
core init does not run twice (the !type branch returns false), so
the only effect of this call is the destructive side effects.

Drop the call. content_clear_subsystem() still runs to clear the
pending flag.

Author: LibretroAdmin

tasks/task_content.c

@@ -1610,10 +1610,7 @@ static bool content_load(content_ctx_info_t *info,
       return false;
 
    if (p_content->flags & CONTENT_ST_FLAG_PENDING_SUBSYSTEM_INIT)
-   {
-      command_event(CMD_EVENT_CORE_INIT, NULL);
       content_clear_subsystem();
-   }
 
 #ifdef HAVE_GFX_WIDGETS
 #ifdef HAVE_CONFIGFILE