xfs: use generic get_unaligned_beXX helpers

Switch the shortform directory code over to use the generic
get_unaligned_beXX helpers instead of reinventing them.  As a result
kill off xfs_arch.h and move the setting of XFS_NATIVE_HOST into
xfs_linux.h.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Alex Elder <aelder@sgi.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
diff --git a/fs/xfs/linux-2.6/xfs_linux.h b/fs/xfs/linux-2.6/xfs_linux.h
index 8633521..d42f814 100644
--- a/fs/xfs/linux-2.6/xfs_linux.h
+++ b/fs/xfs/linux-2.6/xfs_linux.h
@@ -33,7 +33,6 @@
 #endif
 
 #include <xfs_types.h>
-#include <xfs_arch.h>
 
 #include <kmem.h>
 #include <mrlock.h>
@@ -88,6 +87,12 @@
 #include <xfs_buf.h>
 #include <xfs_message.h>
 
+#ifdef __BIG_ENDIAN
+#define XFS_NATIVE_HOST 1
+#else
+#undef XFS_NATIVE_HOST
+#endif
+
 /*
  * Feature macros (disable/enable)
  */