spi: rspi: Re-do the returning value of qspi_transfer_out_in

To reduce complexity of code, drop "ret" then qspi_transfer_out_in function
should return the value of "qspi_trigger_transfer_out_in" directly.

Signed-off-by: Hiep Cao Minh <cm-hiep@jinso.co.jp>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@kernel.org>