hw/sd.c: On CRC error, set CRC error status bit rather than clearing it

If we fail to validate the CRC for an SD command we should be setting
COM_CRC_ERROR, not clearing it. (This bug actually has no effect currently
because sd_req_crc_validate() always returns success.)
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NAndrzej Zaborowski <andrew.zaborowski@intel.com>

hw/sd.c

@@ -1300,7 +1300,7 @@ int sd_do_command(SDState *sd, SDRequest *req,
     }
 
     if (sd_req_crc_validate(req)) {
-        sd->card_status &= ~COM_CRC_ERROR;
+        sd->card_status |= COM_CRC_ERROR;
         return 0;
     }