mlocker: set default log category

contrib/epee/src/mlocker.cpp

@@ -40,6 +40,9 @@
 
 #include <atomic>
 
+#undef MONERO_DEFAULT_LOG_CATEGORY
+#define MONERO_DEFAULT_LOG_CATEGORY "mlocker"
+
 // did an mlock operation previously fail? we only
 // want to log an error once and be done with it
 static std::atomic<bool> previously_failed{ false };