run_interactive(): Fix file descriptor leak when debug is enabled.

Signed-off-by: Joachim Nilsson <troglobit@gmail.com>

helpers.c

@@ -552,9 +552,11 @@ int run_interactive(char *cmd, char *fmt, ...)
 			len     = fread(line, 1, sizeof(line), fp);
 			written = fwrite(line, len, sizeof(char), stderr);
 		} while (len > 0 && written == len);
-		fclose(fp);
 	}
 
+	if (fp)
+		fclose(fp);
+
 	return status;
 }