drivers: SPI: sunxi SPL: fix warning

Somehow an int returning function without a return statement sneaked
in, fix it.
Also fix some whitespace damage on the way.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Jagan Teki <jagan@openedev.com>

drivers/mtd/spi/sunxi_spi_spl.c

@@ -158,9 +158,10 @@ static void spi0_disable_clock(void)
 			     (1 << AHB_RESET_SPI0_SHIFT));
 }
 
-static int spi0_init(void)
+static void spi0_init(void)
 {
 	unsigned int pin_function = SUNXI_GPC_SPI0;
+
 	if (IS_ENABLED(CONFIG_MACH_SUN50I))
 		pin_function = SUN50I_GPC_SPI0;