mmc: omap_hsmmc: Fix Oops in case of data errors

ae4bf788 ("mmc: omap_hsmmc: consolidate error report handling of HSMMC
IRQ") sets both end_cmd and end_trans to 1.

Setting end_cmd to 1 for Data Timeout/CRC leads to NULL pointer dereference of
host->cmd as the command complete has previously been handled.
Set end_cmd only in case of command Timeout/CRC.

Moreover host->cmd->error should not be updated on data error case, only
host->data->error needs to be updated.

Signed-off-by: Balaji T K <balajitk@ti.com>
Reviewed-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Venkatraman S <svenkatr@ti.com>
Signed-off-by: Chris Ball <cjb@laptop.org>