media: venus: core: Fix a potential NULL pointer dereference in an error handling path

The normal path of the function makes the assumption that
'pm_ops->core_power' may be NULL.
We should make the same assumption in the error handling path or a NULL
pointer dereference may occur.

Add the missing test before calling 'pm_ops->core_power'

Fixes: 9e8efdb57879 ("media: venus: core: vote for video-mem path")
Signed-off-by: Christophe JAILLET <[e-mail]>
Signed-off-by: Stanimir Varbanov <[e-mail]>
Signed-off-by: Mauro Carvalho Chehab <[e-mail]>

drivers/media/platform/qcom/venus/core.c

···
 err_video_path:
 	icc_set_bw(core->cpucfg_path, kbps_to_icc(1000), 0);
 err_cpucfg_path:
-	pm_ops->core_power(core, POWER_ON);
+	if (pm_ops->core_power)
+		pm_ops->core_power(core, POWER_ON);
 
 	return ret;
 }