Drop the exporting of empty <linux/byteorder/generic.h>

Fix up the contents of <linux/byteorder/> so that it doesn't export a
content-free generic.h to user space.  This involves:

* Removing the __KERNEL__ tests from generic.h and dropping it from
  Kbuild.
* Wrapping the inclusions of generic.h in both big_endian.h and
  little_endian.h in __KERNEL__ tests.
* Shifting big_endian.h and little_endian.h from header-y to
  unifdef-y in Kbuild.
Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/byteorder/Kbuild

-header-y += big_endian.h
-header-y += little_endian.h
-
-unifdef-y += generic.h
+unifdef-y += big_endian.h
+unifdef-y += little_endian.h
 unifdef-y += swab.h

include/linux/byteorder/big_endian.h

@@ -101,6 +101,8 @@ static inline __u16 __be16_to_cpup(const __be16 *p)
 #define __cpu_to_be16s(x) do {} while (0)
 #define __be16_to_cpus(x) do {} while (0)
 
+#ifdef __KERNEL__
 #include <linux/byteorder/generic.h>
+#endif
 
 #endif /* _LINUX_BYTEORDER_BIG_ENDIAN_H */

include/linux/byteorder/generic.h

@@ -82,12 +82,6 @@
  *
  */
 
-
-#if defined(__KERNEL__)
-/*
- * inside the kernel, we can use nicknames;
- * outside of it, we must avoid POSIX namespace pollution...
- */
 #define cpu_to_le64 __cpu_to_le64
 #define le64_to_cpu __le64_to_cpu
 #define cpu_to_le32 __cpu_to_le32
@@ -176,6 +170,4 @@ static inline void be64_add_cpu(__be64 *var, u64 val)
 	*var = cpu_to_be64(be64_to_cpu(*var) + val);
 }
 
-#endif /* KERNEL */
-
 #endif /* _LINUX_BYTEORDER_GENERIC_H */

include/linux/byteorder/little_endian.h

@@ -101,6 +101,8 @@ static inline __u16 __be16_to_cpup(const __be16 *p)
 #define __cpu_to_be16s(x) __swab16s((x))
 #define __be16_to_cpus(x) __swab16s((x))
 
+#ifdef __KERNEL__
 #include <linux/byteorder/generic.h>
+#endif
 
 #endif /* _LINUX_BYTEORDER_LITTLE_ENDIAN_H */