Refactor apps load_certs/load_crls to work incrementally

Reviewed-by: Richard Levitte <levitte@openssl.org>

apps/s_server.c

diff --git a/apps/s_server.c b/apps/s_server.c
index 93f6083..9d9cb24 100644
--- a/apps/s_server.c
+++ b/apps/s_server.c
@@ -1507,9 +1507,8 @@
             goto end;
         }
         if (s_chain_file) {
-            s_chain = load_certs(s_chain_file, FORMAT_PEM,
-                                 NULL, e, "server certificate chain");
-            if (!s_chain)
+            if (!load_certs(s_chain_file, &s_chain, FORMAT_PEM, NULL, e,
+                            "server certificate chain"))
                 goto end;
         }
 
@@ -1587,9 +1586,8 @@
             goto end;
         }
         if (s_dchain_file) {
-            s_dchain = load_certs(s_dchain_file, FORMAT_PEM,
-                                  NULL, e, "second server certificate chain");
-            if (!s_dchain)
+            if (!load_certs(s_dchain_file, &s_dchain, FORMAT_PEM, NULL, e,
+                            "second server certificate chain"))
                 goto end;
         }