ASoC: atmel-ssc: remove clk_disable_unprepare call from critical section

clk_prepare/unprepare (and indirectly clk_prepare_enable/disable_unprepare)
may sleep and thus cannot be called in critical section.

This patch fix a bug introduced by commit
6f0d9479 where clk_disable_unprepare was
called with user_lock hold.
Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

drivers/misc/atmel-ssc.c

@@ -66,14 +66,19 @@ EXPORT_SYMBOL(ssc_request);
 
 void ssc_free(struct ssc_device *ssc)
 {
+	bool disable_clk = true;
+
 	spin_lock(&user_lock);
-	if (ssc->user) {
+	if (ssc->user)
 		ssc->user--;
-		clk_disable_unprepare(ssc->clk);
-	} else {
+	else {
+		disable_clk = false;
 		dev_dbg(&ssc->pdev->dev, "device already free\n");
 	}
 	spin_unlock(&user_lock);
+
+	if (disable_clk)
+		clk_disable_unprepare(ssc->clk);
 }
 EXPORT_SYMBOL(ssc_free);