Use correct maximum value for MAX_OPS_COUNT

Fixes #1015

av1/common/enums.h

diff --git a/av1/common/enums.h b/av1/common/enums.h
index 35f7d62..66e6c82 100644
--- a/av1/common/enums.h
+++ b/av1/common/enums.h
@@ -300,7 +300,7 @@
 #define OPS_ID_BITS 4
 #define MAX_NUM_OPS_ID (1 << OPS_ID_BITS)
 #define OPS_COUNT_BITS 3
-#define MAX_OPS_COUNT (1 << OPS_COUNT_BITS)
+#define MAX_OPS_COUNT ((1 << OPS_COUNT_BITS) - 1)
 // Atlas
 #define MAX_ATLAS_REGIONS 64
 #define ATLAS_SEG_ID_BITS 3