Guard some of linux/compiler.h with #ifdef __KERNEL__

Signed-off-by: David Woodhouse <[e-mail]>

include/linux/compiler.h

···
 
 #endif /* __ASSEMBLY__ */
 
+#ifdef __KERNEL__
 /*
  * Allow us to mark functions as 'deprecated' and have gcc emit a nice
  * warning for each use, in hopes of speeding the functions removal.
···
 #define __always_inline inline
 #endif
 
+#endif /* __KERNEL__ */
 #endif /* __LINUX_COMPILER_H */