Use #pragma one for all liblog includes

Test: build
Change-Id: I0ffe40853a89acffc1af4fd3838ef488706d23dc
diff --git a/liblog/logger.h b/liblog/logger.h
index 7bb9b20..25ee065 100644
--- a/liblog/logger.h
+++ b/liblog/logger.h
@@ -14,8 +14,7 @@
  * limitations under the License.
  */
 
-#ifndef _LIBLOG_LOGGER_H__
-#define _LIBLOG_LOGGER_H__
+#pragma once
 
 #include <stdatomic.h>
 #include <stdbool.h>
@@ -164,5 +163,3 @@
 extern LIBLOG_HIDDEN int __android_log_transport;
 
 __END_DECLS
-
-#endif /* _LIBLOG_LOGGER_H__ */