RRD files creation async : memory leak

[ymettier]

Hello,

I found a memory leak when you create RRD files with rrdcached plugin enabled with CreateFilesAsync true

LoadPlugin rrdcached
<Plugin rrdcached>
[...]
    CreateFiles true
    CreateFilesAsync true
[...]
</Plugin>

Description of the bug

Source file : utils_rrdcreate.c

Function srrd_create_args_create() starts with a malloc() call :

  args = malloc (sizeof (*args));

Then, for all the life of the args variable, if something goes wrong, srrd_create_args_destroy (args) is called.

However, the args variable is never freed.

Suggestion for a fix

Replace all occurrence of

    srrd_create_args_destroy (args);

with

    srrd_create_args_destroy (args); free(args); args = NULL;

Patch / Pull Request
I'm not writing a patch/pull request for this easy fix because there is another problem with this code, best described in #640 with Pull Request attached.
I updated my PR #640 with the fix for this bug/memory leak.