media: i2c: mt9p031: Remove redundant null check before clk_disable_unprepare

Because clk_disable_unprepare() already checked NULL clock parameter,
so the additional check is unnecessary, just remove it.
Signed-off-by: Xu Wang <vulab@iscas.ac.cn>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

drivers/media/i2c/mt9p031.c

@@ -346,8 +346,7 @@ static void mt9p031_power_off(struct mt9p031 *mt9p031)
 	regulator_bulk_disable(ARRAY_SIZE(mt9p031->regulators),
 			       mt9p031->regulators);
 
-	if (mt9p031->clk)
-		clk_disable_unprepare(mt9p031->clk);
+	clk_disable_unprepare(mt9p031->clk);
 }
 
 static int __mt9p031_set_power(struct mt9p031 *mt9p031, bool on)