[PATCH] Fix sh4 build with __ASSUME_ST_INO_64_BIT redefinition

[Adhemerval Zanella <adhemerval dot zanella at linaro dot org>]

Since 327792c sh4 builds fails with:

../sysdeps/unix/sysv/linux/kernel-features.h:49:0: error: "__ASSUME_ST_INO_64_BIT" redefined [-Werror]
 #define __ASSUME_ST_INO_64_BIT  1
 ^
In file included from ../sysdeps/unix/sysv/linux/sysdep.h:19:0,
                 from ../sysdeps/unix/sysv/linux/sh/sysdep.h:24,
                 from ../sysdeps/unix/sysv/linux/sh/sh4/sysdep.h:4,
                 from <stdin>:1:
../sysdeps/unix/sysv/linux/sh/kernel-features.h:47:0: note: this is the location of the previous definition
 #define __ASSUME_ST_INO_64_BIT 0

It is because sh4 kernel-features.sh is included multiple times
without guards and this patch fixes by adding them. Tested on a
sh4-linux-gnu build.

Also with this issues, is there are strong reason to *not* have include guards
on kernel-features.h?  With current approach, a architecture can't include
Linux default kernel-features.h and redefine it to a different value, only
undefine it (unless it explicit do not include default kernel-features.h,
and I think that's is not the idea).

	* sysdeps/unix/sysv/linux/sh/kernel-features.h: Add include
	guards.
---
 ChangeLog                                    | 5 +++++
 sysdeps/unix/sysv/linux/sh/kernel-features.h | 5 +++++
 2 files changed, 10 insertions(+)

diff --git a/sysdeps/unix/sysv/linux/sh/kernel-features.h b/sysdeps/unix/sysv/linux/sh/kernel-features.h
index ea4fdbc..d03aafa 100644
--- a/sysdeps/unix/sysv/linux/sh/kernel-features.h
+++ b/sysdeps/unix/sysv/linux/sh/kernel-features.h
@@ -17,6 +17,9 @@
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
+#ifndef __KERNEL_FEATURES_SH__
+# define __KERNEL_FEATURES_SH__
+
 /* SH uses socketcall.  */
 #define __ASSUME_SOCKETCALL		1
 
@@ -50,3 +53,5 @@
    the kernel interface for p{read,write}64 adds a dummy long argument
    before the offset.  */
 #define __ASSUME_PRW_DUMMY_ARG	1
+
+#endif
-- 
2.7.4