spi: spi-msm-geni: Return error if setup transfer fails

setup_fifo_xfer/setup_gsi_xfer api may fail while transfer
preparation, return error to the client in such case instead
of advancing with the erroneous transfer to prevent unpredictable
transfer scenarios.

Change-Id: I559fbc1dd26248c639cd0f0e1844dafbada703ce
Signed-off-by: Mukesh Kumar Savaliya <msavaliy@codeaurora.org>