header file cleanup

Test: atest, TreeHugger
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: I03920e51bab3cb704f156ea9c62a0a38fd65a3a9
diff --git a/libbpf_android/include/bpf/BpfUtils.h b/libbpf_android/include/bpf/BpfUtils.h
index e67f664..413d3ff 100644
--- a/libbpf_android/include/bpf/BpfUtils.h
+++ b/libbpf_android/include/bpf/BpfUtils.h
@@ -14,8 +14,7 @@
  * limitations under the License.
  */
 
-#ifndef BPF_BPFUTILS_H
-#define BPF_BPFUTILS_H
+#pragma once
 
 #include <linux/if_ether.h>
 #include <net/if.h>
@@ -34,8 +33,6 @@
 
 constexpr const uint64_t NONEXISTENT_COOKIE = 0;
 
-constexpr const int MINIMUM_API_REQUIRED = 28;
-
 uint64_t getSocketCookie(int sockFd);
 int synchronizeKernelRCU();
 int setrlimitForTest();
@@ -68,5 +65,3 @@
 
 }  // namespace bpf
 }  // namespace android
-
-#endif