spi: slave-mt27xx: Call clk_disable_unprepare() only once in mtk_spi_slave_probe()

A clk_disable_unprepare(mdata->spi_clk) call was immediately used
after a return value check for a devm_spi_register_controller() call
in this function implementation.
Thus call such a function only once instead directly before the check.

This issue was transformed by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Link: https://patch.msgid.link/9e736d33-b07f-40a0-8fb6-8c3212593b77@web.de


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