Avoid computing q val for last spot in gf group

This q value is never used and so its computation is redundant.

Change-Id: I190ed1f29e4d831c304ef240073c761d76476769

av1/encoder/pass2_strategy.c

diff --git a/av1/encoder/pass2_strategy.c b/av1/encoder/pass2_strategy.c
index 1a3ac3f..260ab1b 100644
--- a/av1/encoder/pass2_strategy.c
+++ b/av1/encoder/pass2_strategy.c
@@ -741,7 +741,7 @@
   int bottom_index, top_index;
   int q;
 
-  for (int cur_index = 0; cur_index <= gf_group->size; ++cur_index) {
+  for (int cur_index = 0; cur_index < gf_group->size; ++cur_index) {
     const FRAME_UPDATE_TYPE cur_update_type = gf_group->update_type[cur_index];
     int arf_q = -1;  // Initialize to invalid value, for sanity check later.