header file cleanup

Test: atest, TreeHugger
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: I03920e51bab3cb704f156ea9c62a0a38fd65a3a9

libbpf_android/include/bpf/BpfMap.h

@@ -14,8 +14,7 @@
  * limitations under the License.
  */
 
-#ifndef BPF_BPFMAP_H
-#define BPF_BPFMAP_H
+#pragma once
 
 #include <linux/bpf.h>
 
@@ -258,5 +257,3 @@ class BpfMapRO : public BpfMap<Key, Value> {
 
 }  // namespace bpf
 }  // namespace android
-
-#endif

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 int OVERFLOW_COUNTERSET = 2;
 
 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 @@ static inline bool isAtLeastKernelVersion(unsigned major, unsigned minor, unsign
 
 }  // namespace bpf
 }  // namespace android
-
-#endif

libbpf_android/include/libbpf_android.h

@@ -15,8 +15,7 @@
  * limitations under the License.
  */
 
-#ifndef LIBBPF_SYSTEM_H
-#define LIBBPF_SYSTEM_H
+#pragma once
 
 #include <libbpf.h>
 #include <linux/bpf.h>
@@ -32,5 +31,3 @@ void waitForProgsLoaded();
 
 }  // namespace bpf
 }  // namespace android
-
-#endif