remove meaningless checks for chunks==NULL in dirserv stuff

Also, make it clearer that chunks cannot be NULL

[CID 1031750, 1031751]

src/or/dirserv.c

@@ -1959,13 +1959,12 @@ routerstatus_format_entry(const routerstatus_t *rs, const char *version,
   char published[ISO_TIME_LEN+1];
   char identity64[BASE64_DIGEST_LEN+1];
   char digest64[BASE64_DIGEST_LEN+1];
-  smartlist_t *chunks = NULL;
+  smartlist_t *chunks = smartlist_new();
 
   format_iso_time(published, rs->published_on);
   digest_to_base64(identity64, rs->identity_digest);
   digest_to_base64(digest64, rs->descriptor_digest);
 
-  chunks = smartlist_new();
   smartlist_add_asprintf(chunks,
                    "r %s %s %s%s%s %s %d %d\n",
                    rs->nickname,
@@ -2090,10 +2089,8 @@ routerstatus_format_entry(const routerstatus_t *rs, const char *version,
   result = smartlist_join_strings(chunks, "", 0, NULL);
 
  err:
-  if (chunks) {
-    SMARTLIST_FOREACH(chunks, char *, cp, tor_free(cp));
-    smartlist_free(chunks);
-  }
+  SMARTLIST_FOREACH(chunks, char *, cp, tor_free(cp));
+  smartlist_free(chunks);
 
   return result;
 }

src/or/dirvote.c

@@ -64,7 +64,7 @@ STATIC char *
 format_networkstatus_vote(crypto_pk_t *private_signing_key,
                           networkstatus_t *v3_ns)
 {
-  smartlist_t *chunks;
+  smartlist_t *chunks = smartlist_new();
   const char *client_versions = NULL, *server_versions = NULL;
   char fingerprint[FINGERPRINT_LEN+1];
   char digest[DIGEST_LEN];
@@ -98,7 +98,6 @@ format_networkstatus_vote(crypto_pk_t *private_signing_key,
     server_versions_line = tor_strdup("");
   }
 
-  chunks = smartlist_new();
   {
     char published[ISO_TIME_LEN+1];
     char va[ISO_TIME_LEN+1];
@@ -230,10 +229,9 @@ format_networkstatus_vote(crypto_pk_t *private_signing_key,
  done:
   tor_free(client_versions_line);
   tor_free(server_versions_line);
-  if (chunks) {
-    SMARTLIST_FOREACH(chunks, char *, cp, tor_free(cp));
-    smartlist_free(chunks);
-  }
+
+  SMARTLIST_FOREACH(chunks, char *, cp, tor_free(cp));
+  smartlist_free(chunks);
   return status;
 }