ceph: osd_client: fix endianness bug in osd_req_encode_op()

(cherry picked from commit 065a68f9)

From Al Viro <viro@zeniv.linux.org.uk>

Al Viro noticed that we were using a non-cpu-encoded value in
a switch statement in osd_req_encode_op().  The result would
clearly not work correctly on a big-endian machine.
Signed-off-by: Alex Elder <elder@dreamhost.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

net/ceph/osd_client.c

@@ -278,7 +278,7 @@ static void osd_req_encode_op(struct ceph_osd_request *req,
 {
 	dst->op = cpu_to_le16(src->op);
 
-	switch (dst->op) {
+	switch (src->op) {
 	case CEPH_OSD_OP_READ:
 	case CEPH_OSD_OP_WRITE:
 		dst->extent.offset =