free NULL cleanup

EVP_.*free; this gets:
        EVP_CIPHER_CTX_free EVP_PKEY_CTX_free EVP_PKEY_asn1_free
        EVP_PKEY_asn1_set_free EVP_PKEY_free EVP_PKEY_free_it
        EVP_PKEY_meth_free; and also EVP_CIPHER_CTX_cleanup

Reviewed-by: Kurt Roeckx <kurt@openssl.org>
diff --git a/apps/s_server.c b/apps/s_server.c
index 37c40cb..f97a97d 100644
--- a/apps/s_server.c
+++ b/apps/s_server.c
@@ -2011,10 +2011,8 @@
         sk_X509_CRL_pop_free(crls, X509_CRL_free);
     if (s_dcert)
         X509_free(s_dcert);
-    if (s_key)
-        EVP_PKEY_free(s_key);
-    if (s_dkey)
-        EVP_PKEY_free(s_dkey);
+    EVP_PKEY_free(s_key);
+    EVP_PKEY_free(s_dkey);
     if (s_chain)
         sk_X509_pop_free(s_chain, X509_free);
     if (s_dchain)
@@ -2037,8 +2035,7 @@
         SSL_CTX_free(ctx2);
     if (s_cert2)
         X509_free(s_cert2);
-    if (s_key2)
-        EVP_PKEY_free(s_key2);
+    EVP_PKEY_free(s_key2);
     BIO_free(serverinfo_in);
 # ifndef OPENSSL_NO_NEXTPROTONEG
     if (next_proto.data)