Clean up cfg error handling a bit

Pass in the actual file being used, rather than hardcoded `config.yaml`
Differences between two error messages are not that distinct
Centralize on one and clean up all the `isCustomConfig` tracking

cfg/config_files.go

@@ -84,17 +84,12 @@ func WtfConfigDir() (string, error) {
 }
 
 // LoadWtfConfigFile loads the specified config file
-func LoadWtfConfigFile(filePath string, isCustomConfig bool) *config.Config {
+func LoadWtfConfigFile(filePath string) *config.Config {
 	absPath, _ := expandHomeDir(filePath)
 
 	cfg, err := config.ParseYamlFile(absPath)
 	if err != nil {
-		if isCustomConfig {
-			displayWtfCustomConfigFileLoadError(err)
-		} else {
-			displayWtfConfigFileLoadError(err)
-		}
-
+		displayWtfConfigFileLoadError(absPath, err)
 		os.Exit(1)
 	}