devargs: do not replace already inserted device

devargs: do not replace already inserted device

The devargs of a device can be replaced by a newly allocated one
when trying to probe again the same device (multi-process or
multi-ports scenarios). This is breaking some pointer references.

It can be avoided by copying the new content, freeing the new devargs,
and returning the already inserted pointer.

Signed-off-by: Thomas Monjalon <thomas@monjalon.net>
Tested-by: Darek Stojaczyk <dariusz.stojaczyk@intel.com>
Tested-by: Qi Zhang <qi.z.zhang@intel.com>
Tested-by: Viacheslav Ovsiienko <viacheslavo@mellanox.com>