Commit c312cef223 ("ar71xx: spi-rb4xx fix.") replaced the clk_enable() call
with clk_prepare_enable() to meet the common clock framework requirements.
However it did not change the clk_disable() call in the error patch which
thus leads to imbalance.
Fix the code by using the correct counterpart of clk_prepare_enable() in both
places.
Fixes: c312cef223 ("ar71xx: spi-rb4xx fix.")
Signed-off-by: Gabor Juhos <juhosg@freemail.hu>
6456999731