crypto: tegra - fix missing unlock on error case

Add the missing unlock on the error handling path in function
tegra_aes_get_random() and tegra_aes_rng_reset().

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/drivers/crypto/tegra-aes.c b/drivers/crypto/tegra-aes.c
index 37185e6..19adf1c 100644
--- a/drivers/crypto/tegra-aes.c
+++ b/drivers/crypto/tegra-aes.c
@@ -674,8 +674,10 @@
 	mutex_lock(&aes_lock);
 
 	ret = clk_prepare_enable(dd->aes_clk);
-	if (ret)
+	if (ret) {
+		mutex_unlock(&aes_lock);
 		return ret;
+	}
 
 	ctx->dd = dd;
 	dd->ctx = ctx;
@@ -759,8 +761,10 @@
 	dd->flags = FLAGS_ENCRYPT | FLAGS_RNG;
 
 	ret = clk_prepare_enable(dd->aes_clk);
-	if (ret)
+	if (ret) {
+		mutex_unlock(&aes_lock);
 		return ret;
+	}
 
 	aes_set_key(dd);