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)

apps/spkac.c

diff --git a/apps/spkac.c b/apps/spkac.c
index d1414d6..c081751 100644
--- a/apps/spkac.c
+++ b/apps/spkac.c
@@ -197,5 +197,5 @@
     EVP_PKEY_free(pkey);
     release_engine(e);
     OPENSSL_free(passin);
-    return (ret);
+    return ret;
 }