mei: fix reading large reposnes

While writting to device is limitted to max_msg_length advertized
in client properites the read can be much longer delivered consequiting chunks.

We use krealloc to enlarge the buffer when needed.

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/misc/mei/main.c b/drivers/misc/mei/main.c
index 78b4da5..7c44c8d 100644
--- a/drivers/misc/mei/main.c
+++ b/drivers/misc/mei/main.c
@@ -244,7 +244,7 @@
 		goto out;
 	}
 
-	err = mei_cl_read_start(cl);
+	err = mei_cl_read_start(cl, length);
 	if (err && err != -EBUSY) {
 		dev_dbg(&dev->pdev->dev,
 			"mei start read failure with status = %d\n", err);
@@ -292,9 +292,8 @@
 	}
 	/* now copy the data to user space */
 copy_buffer:
-	dev_dbg(&dev->pdev->dev, "cb->response_buffer size - %d\n",
-	    cb->response_buffer.size);
-	dev_dbg(&dev->pdev->dev, "cb->buf_idx - %lu\n", cb->buf_idx);
+	dev_dbg(&dev->pdev->dev, "buf.size = %d buf.idx= %ld\n",
+	    cb->response_buffer.size, cb->buf_idx);
 	if (length == 0 || ubuf == NULL || *offset > cb->buf_idx) {
 		rets = -EMSGSIZE;
 		goto free;