xl: use xrealloc in domain create

Using bare realloc risks leaking the old pointer if the realloc fails.

Since xrealloc exits on such failures, drop the error handling.

Noticed while fixing, but not related to, CID 1055898.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>

tools/libxl/xl_cmdimpl.c

@@ -2793,12 +2793,8 @@ static uint32_t create_domain(struct domain_create *dom_info)
                 return ERROR_FAIL;
             }
             /* allocate space for the extra config plus two EOLs plus \0 */
-            config_data = realloc(config_data, config_len
+            config_data = xrealloc(config_data, config_len
                 + strlen(extra_config) + 2 + 1);
-            if (!config_data) {
-                fprintf(stderr, "Failed to realloc config_data\n");
-                return ERROR_FAIL;
-            }
             config_len += sprintf(config_data + config_len, "\n%s\n",
                 extra_config);
         }