misc: mei: fix stalled read

This bug caused severe connectivity issue in the LMS application
(LMS is described in  Documentation/misc-devices/mei/mei.txt)

The bug was introduced in patch:
commit 1ccb7b6249f9bc50678e2a383084ed0a34cc9239
staging/mei: propagate error codes up in the write flow

The patch has reverted the return value logic of some fo function but
the conditional in _mei_irq_thread_read function was not swapped
making read always entering the error path

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/misc/mei/interrupt.c

@@ -835,7 +835,7 @@ static int _mei_irq_thread_read(struct mei_device *dev,	s32 *slots,
 			struct mei_cl *cl,
 			struct mei_io_list *cmpl_list)
 {
-	if ((*slots * sizeof(u32)) >= (sizeof(struct mei_msg_hdr) +
+	if ((*slots * sizeof(u32)) < (sizeof(struct mei_msg_hdr) +
 			sizeof(struct hbm_flow_control))) {
 		/* return the cancel routine */
 		list_del(&cb_pos->cb_list);