tool: fix two more allocator mismatches

memory allocated by libcurl (curl_maprintf) must be freed with
curl_free(), and memory allocated by the tool (curlx_strdup via
findfile) must be freed with curlx_free().

- tool_cfgable: ech_config is allocated with curl_maprintf, free it
  with curl_free() instead of tool_safefree()
- config2setopts: known hosts from findfile() is allocated with
  curlx_strdup, free it with curlx_free() instead of curl_free()

Follow-up to b71973c115

Closes #21150

.mailmap

@@ -121,3 +121,4 @@ Andrew Kirillov <akirillo@uk.ibm.com>
 Stephen Farrell <stephen.farrell@cs.tcd.ie>
 Calvin Ruocco <calvin.ruocco@vector.com>
 Hamza Bensliman <benslimanhamza99@gmail.com>
+Kaixuan Li <kaixuan.li@ntu.edu.sg>

src/config2setopts.c

@@ -208,13 +208,20 @@ static CURLcode ssh_setopts(struct OperationConfig *config, CURL *curl,
 
   if(!config->insecure_ok) {
     char *known = config->knownhosts;
-    if(!known)
+    if(!known) {
-      known = findfile(".ssh/known_hosts", FALSE);
+      char *found = findfile(".ssh/known_hosts", FALSE);
+      if(found) {
+        known = curlx_strdup(found);
+        curl_free(found);
+        if(!known)
+          return CURLE_OUT_OF_MEMORY;
+      }
+    }
     if(known) {
       result = my_setopt_str(curl, CURLOPT_SSH_KNOWNHOSTS, known);
       if(result) {
         config->knownhosts = NULL;
-        curl_free(known);
+        curlx_free(known);
         return result;
       }
       /* store it in global to avoid repeated checks */

src/tool_getparam.c

@@ -1267,10 +1267,16 @@ static ParameterError parse_ech(struct OperationConfig *config,
         curlx_fclose(file);
       if(err)
         return err;
-      config->ech_config = curl_maprintf("ecl:%s", tmpcfg);
+      {
-      curlx_free(tmpcfg);
+        char *tmp = curl_maprintf("ecl:%s", tmpcfg);
-      if(!config->ech_config)
+        curlx_free(tmpcfg);
-        return PARAM_NO_MEM;
+        if(!tmp)
+          return PARAM_NO_MEM;
+        config->ech_config = curlx_strdup(tmp);
+        curl_free(tmp);
+        if(!config->ech_config)
+          return PARAM_NO_MEM;
+      }
     } /* file done */
   }
   else {