BLUETOOTH: GAP: Write 248 char name length to the chip while BT ON/OFF

This fix will write the exact 248 character local name to the chip
which is exists in the storage instead of writing the default name
while doing BT ON/OFF locally.

Change-Id: I702af8fa8d0affda509de7a9f17af8922e410286
CRs-Fixed: 685872
diff --git a/btif/src/btif_dm.c b/btif/src/btif_dm.c
index 46e7c62..b0545d9 100644
--- a/btif/src/btif_dm.c
+++ b/btif/src/btif_dm.c
@@ -1660,7 +1660,7 @@
              bt_status_t status;
              bt_property_t prop;
              prop.type = BT_PROPERTY_BDNAME;
-             prop.len = BD_NAME_LEN;
+             prop.len = BD_NAME_LEN + 1;
              prop.val = (void*)bdname;
 
              status = btif_storage_get_adapter_property(&prop);