util: improve streams.h:FindByte() performance

Avoid use of the expensive mod operator (%) when calculating the
buffer offset. No functional difference.

Co-authored-by: Hennadii Stepanov <32963518+hebasto@users.noreply.github.com>

src/bench/streams_findbyte.cpp

@@ -20,7 +20,7 @@ static void FindByte(benchmark::Bench& bench)
 
     bench.run([&] {
         bf.SetPos(0);
-        bf.FindByte(1);
+        bf.FindByte(std::byte(1));
     });
 
     // Cleanup