Revert "Removed mutex locking from get and set of log level #4809"

This reverts commit 3eef49d5c9.

src/lib/base/Log.cpp

@@ -260,12 +260,14 @@ Log::setFilter(const char* maxPriority)
 void
 Log::setFilter(int maxPriority)
 {
+	ArchMutexLock lock(m_mutex);
 	m_maxPriority = maxPriority;
 }
 
 int
 Log::getFilter() const
 {
+	ArchMutexLock lock(m_mutex);
 	return m_maxPriority;
 }