Revert "parser: Tolerate late completing tasks after flushing"

This reverts commit 433593c5.
This wasn't enough to fix the problem, as a refresh would:
- Invoke flush, setting the flushed flag to true
- Invoke restore, immediatly setting the flag back to false

src/parser/Parser.cpp

@@ -45,7 +45,6 @@ Parser::Parser( MediaLibrary* ml, FsHolder* fsHolder )
     , m_callback( nullptr )
     , m_opScheduled( 0 )
     , m_opDone( 0 )
-    , m_flushed( false )
     , m_completionSignaled( false )
 {
 }
@@ -70,7 +69,6 @@ void Parser::parse( std::shared_ptr<Task> task )
     {
         std::lock_guard<compat::Mutex> lock{ m_mutex };
         m_opScheduled += 1;
-        m_flushed = false;
         updateStats();
     }
     m_serviceWorkers[0]->parse( std::move( task ) );
@@ -135,7 +133,6 @@ void Parser::flush()
     std::lock_guard<compat::Mutex> lock{ m_mutex };
     m_opDone = 0;
     m_opScheduled = 0;
-    m_flushed = true;
 }
 
 void Parser::rescan()
@@ -160,7 +157,6 @@ void Parser::restore()
     {
         std::lock_guard<compat::Mutex> lock{ m_mutex };
         m_opScheduled += tasks.size();
-        m_flushed = false;
         updateStats();
     }
     m_serviceWorkers[0]->parse( std::move( tasks ) );
@@ -203,14 +199,7 @@ void Parser::updateStats()
 {
     if ( m_callback == nullptr )
         return;
-    if ( m_opScheduled < m_opDone )
-    {
-        /* Tolerate completing tasks after a flush */
-        if ( m_flushed == true )
-            m_opDone = m_opScheduled;
-        else
-            assert( !"Unexpected completed task" );
-    }
+    assert( m_opScheduled >= m_opDone );
     /*
      * We don't want to spam the callback receiver each time we're done parsing
      * an item, however we must signal progress when:

src/parser/Parser.h

@@ -104,7 +104,6 @@ private:
     IMediaLibraryCb* m_callback;
     uint32_t m_opScheduled;
     uint32_t m_opDone;
-    bool m_flushed; /* Helper flag to handle late completing tasks */
     bool m_completionSignaled;
 };