hal: Correct the multi-channel output usecase selection

Both Multi-channel output on HDMI and Compress offload playback on
HDMI use cases request for a stream with AUDIO_OUTPUT_FLAG_DIRECT.
The current logic would then result selection MULTI_CH usecase.
Fix this by checking for complete match of flags to select the
use case.

Change-Id: I66df94af6c3b837a6c8054282364e1acf78e6e0f
diff --git a/hal/audio_hw.c b/hal/audio_hw.c
index 873e5e2..00bb65d 100644
--- a/hal/audio_hw.c
+++ b/hal/audio_hw.c
@@ -1975,7 +1975,7 @@
     out->handle = handle;
 
     /* Init use case and pcm_config */
-    if (out->flags & AUDIO_OUTPUT_FLAG_DIRECT &&
+    if (out->flags == AUDIO_OUTPUT_FLAG_DIRECT &&
         out->devices & AUDIO_DEVICE_OUT_AUX_DIGITAL) {
         pthread_mutex_lock(&adev->lock);
         ret = read_hdmi_channel_masks(out);