sdm: Fix output fences on prepare failure.

Prepare failure results in repeating the older frame, without issuing a
commit. Output fences i.e., release and retire get populated during start.
These need to be cleared in case of prepare failure, else it will lead
to deadlocks.

CRs-Fixed: 3321131
Change-Id: Iec1d2fb8c14b5748fb273533fa4f2c012bf6c2b6

sdm/libs/core/display_base.cpp

@@ -1327,6 +1327,13 @@ DisplayError DisplayBase::CommitOrPrepare(LayerStack *layer_stack) {
     } else {
       DLOGE("Prepare failed: %d", error);
     }
+    // Clear fences
+    DLOGI("Clearing fences on input layers on display %d-%d", display_id_, display_type_);
+    for (auto &layer : layer_stack->layers) {
+      layer->input_buffer.release_fence = nullptr;
+    }
+    layer_stack->retire_fence = nullptr;
+
     return error;
   }