Use "#pragma once" to prevent repeated header file inclusion

src/nix-env/profiles.hh

@@ -1,5 +1,4 @@
-#ifndef __PROFILES_H
-#define __PROFILES_H
+#pragma once
 
 #include "types.hh"
 #include "pathlocks.hh"
@@ -54,6 +53,3 @@ void lockProfile(PathLocks & lock, const Path & profile);
 string optimisticLockProfile(const Path & profile);
 
 }
-
-
-#endif /* !__PROFILES_H */

src/nix-env/user-env.hh

@@ -1,5 +1,4 @@
-#ifndef __USER_ENV_H
-#define __USER_ENV_H
+#pragma once
 
 #include "get-drvs.hh"
 
@@ -12,9 +11,3 @@ bool createUserEnv(EvalState & state, DrvInfos & elems,
     const string & lockToken);
 
 }
-
-#endif /* !__USER_ENV_H */
-
-
-
-