fix microblaze definition of struct stat

the erroneous definition was missed because with works with qemu
user-level emulation, which also has the wrong definition. the actual
kernel uses the asm-generic generic definition.

(cherry picked from commit d69ab5b3686acf75fdf5db6fad19c2c6a510bb4f)

arch/microblaze/bits/stat.h

@@ -4,8 +4,7 @@
 struct stat
 {
 	dev_t st_dev;
-	int __st_dev_padding;
-	long __st_ino_truncated;
+	ino_t st_ino;
 	mode_t st_mode;
 	nlink_t st_nlink;
 	uid_t st_uid;
@@ -19,5 +18,5 @@ struct stat
 	struct timespec st_atim;
 	struct timespec st_mtim;
 	struct timespec st_ctim;
-	ino_t st_ino;
+	unsigned __unused[2];
 };