output/Control: rename "cond" to "wake_cond"

Prepare for adding another Cond attribute.

src/output/Control.cxx

@@ -128,7 +128,7 @@ AudioOutputControl::CommandAsync(Command cmd) noexcept
 	assert(IsCommandFinished());
 
 	command = cmd;
-	cond.signal();
+	wake_cond.signal();
 }
 
 void
@@ -298,7 +298,7 @@ AudioOutputControl::LockPlay() noexcept
 
 	if (IsOpen() && !in_playback_loop && !woken_for_play) {
 		woken_for_play = true;
-		cond.signal();
+		wake_cond.signal();
 	}
 }
 
@@ -346,7 +346,7 @@ AudioOutputControl::LockAllowPlay() noexcept
 
 	allow_play = true;
 	if (IsOpen())
-		cond.signal();
+		wake_cond.signal();
 }
 
 void

src/output/Control.hxx

@@ -91,7 +91,7 @@ class AudioOutputControl {
 	 * This condition object wakes up the output thread after
 	 * #command has been set.
 	 */
-	Cond cond;
+	Cond wake_cond;
 
 	/**
 	 * Additional data for #command.  Protected by #mutex.

src/output/Thread.cxx

@@ -218,7 +218,7 @@ AudioOutputControl::WaitForDelay() noexcept
 		if (delay <= std::chrono::steady_clock::duration::zero())
 			return true;
 
-		(void)cond.timed_wait(mutex, delay);
+		(void)wake_cond.timed_wait(mutex, delay);
 
 		if (command != Command::NONE)
 			return false;
@@ -491,7 +491,7 @@ AudioOutputControl::Task() noexcept
 
 		if (command == Command::NONE) {
 			woken_for_play = false;
-			cond.wait(mutex);
+			wake_cond.wait(mutex);
 		}
 	}
 }