libusbg: Initialize gadget attributes and strings while gadget creation.
libusbg: Initialize gadget attributes and strings while gadget creation.

Fix gadget_create_gadget function to initialize gadget attributes
and strings with default values provided by kernel.

Signed-off-by: Krzysztof Opasiak <8064eda6f94b3817252b7d7649cf754592f63500@samsung.com>

pszewczyk/libusbg,pszewczyk/libusbg