spi: spi-qpic-snand: return early on error from qcom_spi_io_op()

When submitting of the descriptors fails, it is quite likely that
the register read buffer contains no valid data. Even if the data
is valid the function returns with an error code anyway.

Change the code to return early if qcom_submit_descs() fails to
avoid superfluously copying possibly invalid data.

Also change the return statement at the end of the function to use
zero value to indicate success obviusly.

Signed-off-by: Gabor Juhos <j4g8y7@gmail.com>
Link: https://patch.msgid.link/20250515-qpic-snand-early-error-v1-1-681c87611213@gmail.com


Signed-off-by: Mark Brown <broonie@kernel.org>