media: meson: vdec_1: Refactor vdec_1_stop()

Factor out all the power off logic, except the clk_disable_unprepare(),
to a new function __vdec_1_stop().

This allows vdec_1_start() to explicitly clean-out the clock during the
error-path.

The following smatch warning is fixed:
drivers/staging/media/meson/vdec/vdec_1.c:239 vdec_1_start() warn: 'core->vdec_1_clk' from clk_prepare_enable() not released on lines: 239.

Signed-off-by: Ricardo Ribalda <[e-mail]>
Signed-off-by: Sakari Ailus <[e-mail]>
Signed-off-by: Hans Verkuil <[e-mail]>

drivers/staging/media/meson/vdec/vdec_1.c

···
 	return amvdec_read_dos(core, VLD_MEM_VIFIFO_LEVEL);
 }
 
-static int vdec_1_stop(struct amvdec_session *sess)
+static void __vdec_1_stop(struct amvdec_session *sess)
 {
 	struct amvdec_core *core = sess->core;
 	struct amvdec_codec_ops *codec_ops = sess->fmt_out->codec_ops;
···
 		regmap_update_bits(core->regmap_ao, AO_RTI_GEN_PWR_SLEEP0,
 				   GEN_PWR_VDEC_1, GEN_PWR_VDEC_1);
 
-	clk_disable_unprepare(core->vdec_1_clk);
-
 	if (sess->priv)
 		codec_ops->stop(sess);
+}
+
+static int vdec_1_stop(struct amvdec_session *sess)
+{
+	struct amvdec_core *core = sess->core;
+
+	__vdec_1_stop(sess);
+
+	clk_disable_unprepare(core->vdec_1_clk);
 
 	return 0;
 }
···
 	return 0;
 
 stop:
-	vdec_1_stop(sess);
+	__vdec_1_stop(sess);
+	clk_disable_unprepare(core->vdec_1_clk);
 	return ret;
 }