media: mtk-mdp: use IS_ERR to check return value of of_clk_get

[Pan Bian]

Function of_clk_get() returns an ERR_PTR on failures. In file
mtk_mdp_commp.c, its return value is checked against NULL. Such checks
cannot prevent from accessing bad memory. This patch replaces the NULL
checks with IS_ERR checks.

Signed-off-by: Pan Bian <bianpan2...@163.com>
---
 drivers/media/platform/mtk-mdp/mtk_mdp_comp.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/media/platform/mtk-mdp/mtk_mdp_comp.c 
b/drivers/media/platform/mtk-mdp/mtk_mdp_comp.c
index aa8f9fd..54bb716 100644
--- a/drivers/media/platform/mtk-mdp/mtk_mdp_comp.c
+++ b/drivers/media/platform/mtk-mdp/mtk_mdp_comp.c
@@ -75,7 +75,7 @@ void mtk_mdp_comp_clock_on(struct device *dev, struct 
mtk_mdp_comp *comp)
        }
 
        for (i = 0; i < ARRAY_SIZE(comp->clk); i++) {
-               if (!comp->clk[i])
+               if (IS_ERR(comp->clk[i]))
                        continue;
                err = clk_prepare_enable(comp->clk[i]);
                if (err)
@@ -90,7 +90,7 @@ void mtk_mdp_comp_clock_off(struct device *dev, struct 
mtk_mdp_comp *comp)
        int i;
 
        for (i = 0; i < ARRAY_SIZE(comp->clk); i++) {
-               if (!comp->clk[i])
+               if (IS_ERR(comp->clk[i]))
                        continue;
                clk_disable_unprepare(comp->clk[i]);
        }
-- 
1.9.1