Change to uint8_t for flags

In reviewing previous commit to reduce size of SequenceHeader struct,
Wan-Teh brought up that these two relevant flags should be changed to
use uint8_t for consistency.

Change-Id: Ie24e53b5b8ca4480953ec4ded28cfd5e38e25606
diff --git a/av1/common/onyxc_int.h b/av1/common/onyxc_int.h
index 614643a..6d8c082 100644
--- a/av1/common/onyxc_int.h
+++ b/av1/common/onyxc_int.h
@@ -381,9 +381,9 @@
 
   uint8_t disable_cdf_update;
   int allow_high_precision_mv;
-  int cur_frame_force_integer_mv;  // 0 the default in AOM, 1 only integer
+  uint8_t cur_frame_force_integer_mv;  // 0 the default in AOM, 1 only integer
 
-  int allow_screen_content_tools;
+  uint8_t allow_screen_content_tools;
   int allow_intrabc;
   int allow_warped_motion;