rtase: Fix error code in rtase_init_board()

Return an error if dma_set_mask_and_coherent() fails.  Don't return
success.

Fixes: a36e9f5c ("rtase: Add support for a pci table in this module")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/f53ed942-5ac2-424b-a1ed-9473c599905e@stanley.mountain


Signed-off-by: Jakub Kicinski <kuba@kernel.org>