Add local to pan_api.cc

Bug: 233604485
Test: Manual, connected BT and played audio
Tag: #security
Ignore-AOSP-First: Security
Change-Id: Ibb7fffccde731ecb7c12b8ddf212f02f156ffd89
(cherry picked from commit ca6cac4996a2a8c5369c646648ccbc49e29658c6)
Merged-In: Ibb7fffccde731ecb7c12b8ddf212f02f156ffd89
diff --git a/system/stack/pan/pan_api.cc b/system/stack/pan/pan_api.cc
index 0352ed4..40b26a3 100644
--- a/system/stack/pan/pan_api.cc
+++ b/system/stack/pan/pan_api.cc
@@ -541,6 +541,7 @@
     return PAN_FAILURE;
   }
 
+  uint16_t len = p_buf->len;
   result = BNEP_WriteBuf(pcb->handle, dst, p_buf, protocol, &src, ext);
   if (result == BNEP_IGNORE_CMD) {
     PAN_TRACE_DEBUG("PAN ignored data buf write to PANU");
@@ -552,7 +553,7 @@
     return (tPAN_RESULT)result;
   }
 
-  pcb->write.octets += p_buf->len;
+  pcb->write.octets += len;
   pcb->write.packets++;
 
   PAN_TRACE_DEBUG("PAN successfully sent data buf to the PANU");