Fix header guard styles

PiperOrigin-RevId: 543675969

nullability/pointer_nullability_lattice.h

diff --git a/nullability/pointer_nullability_lattice.h b/nullability/pointer_nullability_lattice.h
index 67d58eb..5360239 100644
--- a/nullability/pointer_nullability_lattice.h
+++ b/nullability/pointer_nullability_lattice.h
@@ -2,8 +2,8 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 
-#ifndef THIRD_PARTY_CRUBIT_NULLABILITY_POINTER_NULLABILITY_LATTICE_H_
-#define THIRD_PARTY_CRUBIT_NULLABILITY_POINTER_NULLABILITY_LATTICE_H_
+#ifndef CRUBIT_NULLABILITY_POINTER_NULLABILITY_LATTICE_H_
+#define CRUBIT_NULLABILITY_POINTER_NULLABILITY_LATTICE_H_
 
 #include <optional>
 #include <ostream>
@@ -83,4 +83,4 @@
 }  // namespace tidy
 }  // namespace clang
 
-#endif  // THIRD_PARTY_CRUBIT_NULLABILITY_POINTER_NULLABILITY_LATTICE_H_
+#endif  // CRUBIT_NULLABILITY_POINTER_NULLABILITY_LATTICE_H_

nullability/test/check_diagnostics.h

diff --git a/nullability/test/check_diagnostics.h b/nullability/test/check_diagnostics.h
index 9d05b76..79633df 100644
--- a/nullability/test/check_diagnostics.h
+++ b/nullability/test/check_diagnostics.h
@@ -2,8 +2,8 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 
-#ifndef THIRD_PARTY_CRUBIT_NULLABILITY_TEST_CHECK_DIAGNOSTICS_H_
-#define THIRD_PARTY_CRUBIT_NULLABILITY_TEST_CHECK_DIAGNOSTICS_H_
+#ifndef CRUBIT_NULLABILITY_TEST_CHECK_DIAGNOSTICS_H_
+#define CRUBIT_NULLABILITY_TEST_CHECK_DIAGNOSTICS_H_
 
 #include "llvm/ADT/StringRef.h"
 
@@ -22,4 +22,4 @@
 }  // namespace tidy
 }  // namespace clang
 
-#endif  // THIRD_PARTY_CRUBIT_NULLABILITY_TEST_CHECK_DIAGNOSTICS_H_
+#endif  // CRUBIT_NULLABILITY_TEST_CHECK_DIAGNOSTICS_H_