metrics-ipmi-blobs: util: openbmc uses pragma once

Change-Id: I91e2b9fdd1eaabae877168c03c9e6c5d0dc57b40
Signed-off-by: William A. Kennington III <wak@google.com>
diff --git a/metrics-ipmi-blobs/util.hpp b/metrics-ipmi-blobs/util.hpp
index b74b589..33ed997 100644
--- a/metrics-ipmi-blobs/util.hpp
+++ b/metrics-ipmi-blobs/util.hpp
@@ -1,5 +1,4 @@
-#ifndef _UTIL_HPP_
-#define _UTIL_HPP_
+#pragma once
 
 #include <string>
 #include <string_view>
@@ -29,5 +28,3 @@
 std::string trimStringRight(std::string_view s);
 
 } // namespace metric_blob
-
-#endif
\ No newline at end of file