Format buffer state in hex instead of decimal.

Buffer state and fence state are more readable in hex.

Test: None
Bug: None
Change-Id: Id3de357e0f8af2b434aac92925ceb4ec2b5e7d2c
diff --git a/services/vr/bufferhubd/producer_channel.cpp b/services/vr/bufferhubd/producer_channel.cpp
index 162065b..6bf6029 100644
--- a/services/vr/bufferhubd/producer_channel.cpp
+++ b/services/vr/bufferhubd/producer_channel.cpp
@@ -284,8 +284,8 @@
   if (!active_clients_bit_mask_->compare_exchange_weak(
           current_active_clients_bit_mask, updated_active_clients_bit_mask,
           std::memory_order_acq_rel, std::memory_order_acquire)) {
-    ALOGE("Current active clients bit mask is changed to %" PRIu64
-          ", which was expected to be %" PRIu64 ".",
+    ALOGE("Current active clients bit mask is changed to %" PRIx64
+          ", which was expected to be %" PRIx64 ".",
           updated_active_clients_bit_mask, current_active_clients_bit_mask);
     return ErrorStatus(EBUSY);
   }