ath10k: fix dma_mapping_error() handling

ath10k: fix dma_mapping_error() handling

commit 5e55e3cbd1042cffa6249f22c10585e63f8a29bf upstream.

The function returns 1 when DMA mapping fails. The
driver would return bogus values and could
possibly confuse itself if DMA failed.

Fixes: 767d34fc67af ("ath10k: remove DMA mapping wrappers")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>