Cycles: Fix unhandled enumerator in OSL switch

Unsigned int is not supported by OSL as far as i concerned, so should not
really matter here. However, might be wrong and perhaps more proper idea
would be so set it as regular int?

intern/cycles/render/osl.cpp

@@ -891,6 +891,7 @@ void OSLCompiler::parameter(ShaderNode* node, const char *name)
 		case SocketType::NODE:
 		case SocketType::NODE_ARRAY:
 		case SocketType::UNDEFINED:
+		case SocketType::UINT:
 		{
 			assert(0);
 			break;