Remove parentheses of return.

Since return is inconsistent, I removed unnecessary parentheses and
unified them.

Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/4541)
diff --git a/crypto/dsa/dsa_lib.c b/crypto/dsa/dsa_lib.c
index ed55d75..e730e8e 100644
--- a/crypto/dsa/dsa_lib.c
+++ b/crypto/dsa/dsa_lib.c
@@ -160,17 +160,17 @@
     i = i2d_ASN1_INTEGER(&bs, NULL);
     i += i;                     /* r and s */
     ret = ASN1_object_size(1, i, V_ASN1_SEQUENCE);
-    return (ret);
+    return ret;
 }
 
 int DSA_set_ex_data(DSA *d, int idx, void *arg)
 {
-    return (CRYPTO_set_ex_data(&d->ex_data, idx, arg));
+    return CRYPTO_set_ex_data(&d->ex_data, idx, arg);
 }
 
 void *DSA_get_ex_data(DSA *d, int idx)
 {
-    return (CRYPTO_get_ex_data(&d->ex_data, idx));
+    return CRYPTO_get_ex_data(&d->ex_data, idx);
 }
 
 int DSA_security_bits(const DSA *d)