srsue,phy: fix setting of PHY log level

probably a regression from the new log system integration.
it was disabling PHY logs, from PRACH for example.

srsue/src/phy/phy.cc

@@ -135,7 +135,7 @@ int phy::init(const phy_args_t& args_)
   {
     log_h = std::unique_ptr<srslte::log_filter>(new srslte::log_filter);
     log_h->init("PHY", logger, true);
-    log_h->set_level(args.log.phy_lib_level);
+    log_h->set_level(args.log.phy_level);
     log_h->set_hex_limit(args.log.phy_hex_limit);
   }