checksrc: disallow spaces before labels

Out of 415 labels throughout the code base, 86 of those labels were
not at the start of the line. Which means labels always at the start of
the line is the favoured style overall with 329 instances.

Out of the 86 labels not at the start of the line:
* 75 were indented with the same indentation level of the following line
* 8 were indented with exactly one space
* 2 were indented with one fewer indentation level then the following
  line
* 1 was indented with the indentation level of the following line minus
  three space (probably unintentional)

Co-Authored-By: Viktor Szakats

Closes #11134

src/tool_formparse.c

@@ -900,7 +900,7 @@ int formparse(struct OperationConfig *config,
     goto fail;
   }
   err = 0;
-  fail:
+fail:
   Curl_safefree(contents);
   curl_slist_free_all(headers);
   return err;

src/tool_operate.c

@@ -624,7 +624,7 @@ static CURLcode post_per_transfer(struct GlobalConfig *global,
       return CURLE_OK;
     }
   } /* if retry_numretries */
-  noretry:
+noretry:
 
   if((global->progressmode == CURL_PROGRESS_BAR) &&
      per->progressbar.calls)

src/tool_operhlp.c

@@ -170,7 +170,7 @@ CURLcode add_file_name_to_url(CURL *curl, char **inurlp, const char *filename)
       /* nothing to do */
       result = CURLE_OK;
   }
-  fail:
+fail:
   curl_url_cleanup(uh);
   curl_free(path);
   return result;

src/tool_setopt.c

@@ -296,7 +296,7 @@ CURLcode tool_setopt_enum(CURL *curl, struct GlobalConfig *config,
   if(ret)
     warnf(config, "option %s returned error (%d)\n", name, (int)ret);
 #endif
-  nomem:
+nomem:
   return ret;
 }
 
@@ -338,7 +338,7 @@ CURLcode tool_setopt_flags(CURL *curl, struct GlobalConfig *config,
       CODE2("%s%ldL);", preamble, rest);
   }
 
- nomem:
+nomem:
   return ret;
 }
 
@@ -381,7 +381,7 @@ CURLcode tool_setopt_bitmask(CURL *curl, struct GlobalConfig *config,
       CODE2("%s%luUL);", preamble, rest);
   }
 
- nomem:
+nomem:
   return ret;
 }
 
@@ -407,7 +407,7 @@ static CURLcode libcurl_generate_slist(struct curl_slist *slist, int *slistno)
                                        *slistno, *slistno, escaped);
   }
 
- nomem:
+nomem:
   Curl_safefree(escaped);
   return ret;
 }
@@ -590,7 +590,7 @@ CURLcode tool_setopt_slist(CURL *curl, struct GlobalConfig *config,
       CODE2("curl_easy_setopt(hnd, %s, slist%d);", name, i);
   }
 
- nomem:
+nomem:
   return ret;
 }
 
@@ -704,7 +704,7 @@ CURLcode tool_setopt(CURL *curl, bool str, struct GlobalConfig *global,
     }
   }
 
- nomem:
+nomem:
   Curl_safefree(escaped);
   return ret;
 }

src/tool_urlglob.c

@@ -295,7 +295,7 @@ static CURLcode glob_range(struct URLGlob *glob, char **patternp,
       }
     }
 
-    fail:
+fail:
     *posp += (pattern - *patternp);
 
     if(!endp || !step_n ||

src/tool_xattr.c

@@ -75,7 +75,7 @@ char *stripcredentials(const char *url)
 
     return nurl;
   }
-  error:
+error:
   curl_url_cleanup(u);
   return NULL;
 }