cpplint header guard style

src/kaleidoscope/util/crc16.h

@@ -31,8 +31,7 @@
   ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   POSSIBILITY OF SUCH DAMAGE. */
 
-#ifndef _UTIL_CRC16_H_
-#define _UTIL_CRC16_H_
+#pragma once
 
 #include <stdint.h>
 
@@ -89,6 +88,3 @@ static inline uint8_t _crc_ibutton_update(uint8_t crc, uint8_t data) {
   }
   return crc;
 }
-
-#endif
-