Revert "ceph: make members in struct ceph_mds_request_args_ext a union"

This reverts commit 3af5ae22.

ceph_mds_request_args_ext was already (and remains to be) a union.  An
additional anonymous union inside is bogus:

    union ceph_mds_request_args_ext {
        union {
            union ceph_mds_request_args old;
            struct { ... } __attribute__ ((packed)) setattr_ext;
        };
    }
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Xiubo Li <xiubli@redhat.com>

include/linux/ceph/ceph_fs.h

@@ -467,19 +467,17 @@ union ceph_mds_request_args {
 } __attribute__ ((packed));
 
 union ceph_mds_request_args_ext {
-	union {
-		union ceph_mds_request_args old;
-		struct {
-			__le32 mode;
-			__le32 uid;
-			__le32 gid;
-			struct ceph_timespec mtime;
-			struct ceph_timespec atime;
-			__le64 size, old_size;       /* old_size needed by truncate */
-			__le32 mask;                 /* CEPH_SETATTR_* */
-			struct ceph_timespec btime;
-		} __attribute__ ((packed)) setattr_ext;
-	};
+	union ceph_mds_request_args old;
+	struct {
+		__le32 mode;
+		__le32 uid;
+		__le32 gid;
+		struct ceph_timespec mtime;
+		struct ceph_timespec atime;
+		__le64 size, old_size;       /* old_size needed by truncate */
+		__le32 mask;                 /* CEPH_SETATTR_* */
+		struct ceph_timespec btime;
+	} __attribute__ ((packed)) setattr_ext;
 };
 
 #define CEPH_MDS_FLAG_REPLAY		1 /* this is a replayed op */