Fix multiple inclusion guards to match new pathnames

Change-Id: Id7735be1d75bc315733b1773fba45c1deb8ace43
diff --git a/runtime/base/unix_file/string_file.h b/runtime/base/unix_file/string_file.h
index 8944373..26904f8 100644
--- a/runtime/base/unix_file/string_file.h
+++ b/runtime/base/unix_file/string_file.h
@@ -14,8 +14,8 @@
  * limitations under the License.
  */
 
-#ifndef BASE_UNIX_FILE_STRING_FILE_H_
-#define BASE_UNIX_FILE_STRING_FILE_H_
+#ifndef ART_RUNTIME_BASE_UNIX_FILE_STRING_FILE_H_
+#define ART_RUNTIME_BASE_UNIX_FILE_STRING_FILE_H_
 
 #include <stdint.h>
 
@@ -56,4 +56,4 @@
 
 }  // namespace unix_file
 
-#endif  // BASE_UNIX_FILE_STRING_FILE_H_
+#endif  // ART_RUNTIME_BASE_UNIX_FILE_STRING_FILE_H_