[S390] locking problem with __cpcmd.

Changeset 740b5706b9c4b3767f597b3ea76654c6f2a800b2 moved the protecting
spinlock from __cpcmd to cpcmd. Therefore vmcp can no longer use __cpcmd,
instead we have to use cpcmd.

Signed-off-by: Christian Borntraeger <cborntra@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/drivers/s390/char/vmcp.c b/drivers/s390/char/vmcp.c
index 1678b6c..a420cd0 100644
--- a/drivers/s390/char/vmcp.c
+++ b/drivers/s390/char/vmcp.c
@@ -117,7 +117,7 @@
 		return -ENOMEM;
 	}
 	debug_text_event(vmcp_debug, 1, cmd);
-	session->resp_size = __cpcmd(cmd, session->response,
+	session->resp_size = cpcmd(cmd, session->response,
 				     session->bufsize,
 				     &session->resp_code);
 	up(&session->mutex);