Fix a baseline build error

Change-Id: I9b92caa9d65a3b062762c270c89018c8e08eba0f

av1/encoder/bitstream.c

diff --git a/av1/encoder/bitstream.c b/av1/encoder/bitstream.c
index ad8d8f4..6c91b0c 100644
--- a/av1/encoder/bitstream.c
+++ b/av1/encoder/bitstream.c
@@ -3667,13 +3667,12 @@
 #endif  // CONFIG_EXT_REFS
 
 static int get_refresh_mask(AV1_COMP *cpi) {
+  int refresh_mask = 0;
 #if CONFIG_EXT_REFS
 #if USE_GF16_MULTI_LAYER
   if (cpi->rc.baseline_gf_interval == 16) return get_refresh_mask_gf16(cpi);
 #endif  // USE_GF16_MULTI_LAYER
 
-  int refresh_mask = 0;
-
   // NOTE(zoeliu): When LAST_FRAME is to get refreshed, the decoder will be
   // notified to get LAST3_FRAME refreshed and then the virtual indexes for all
   // the 3 LAST reference frames will be updated accordingly, i.e.: