kdbus_cmd_name_acquire returns -EALREADY if connection is already owner of the name, fixed memory freeing

kdbus_cmd_name_acquire from now returns -EALREADY if connection wants to acquire well-known name that
it is already owner of. This situation wasn't signalled before. Also freeing alocated memory was fixed
in that function.

Signed-off-by: Radoslaw Pajak <r.pajak@samsung.com>
Add dumping \0-bytes records.

Signed-off-by: Daniel Kowalski <d.kowalski@samsung.com>