In AvatarFactoryModule.SetApperance(), perform ValidateBakedTextureCache() in the same thread rather than on another one.

The caller is already an async thread from LLClientView so this doesn't hold up the client.
However, launching on a separate thread does remove the effect of m_setAppearanceLock
This was potentially allowing two different SetAppearance threads to interfere with each other, though this probably rarely happens, if at all.

OpenSim/Region/CoreModules/Avatar/AvatarFactory/AvatarFactoryModule.cs

@@ -150,13 +150,13 @@ namespace OpenSim.Region.CoreModules.Avatar.AvatarFactory
                     changed = sp.Appearance.SetTextureEntries(textureEntry) || changed;
 
                     m_log.InfoFormat("[AVFACTORY]: received texture update for {0}", sp.UUID);
-                    Util.FireAndForget(delegate(object o) { ValidateBakedTextureCache(sp, false); });
+                    ValidateBakedTextureCache(sp, false);
 
                     // This appears to be set only in the final stage of the appearance
                     // update transaction. In theory, we should be able to do an immediate
                     // appearance send and save here.
-
                 }
+                
                 // save only if there were changes, send no matter what (doesn't hurt to send twice)
                 if (changed)
                     QueueAppearanceSave(sp.ControllingClient.AgentId);