usb: gadget: aspeed: Add NULL pointer check in ast_vhub_init_dev()

usb: gadget: aspeed: Add NULL pointer check in ast_vhub_init_dev()

The variable d->name, returned by devm_kasprintf(), could be NULL.
A pointer check is added to prevent potential NULL pointer dereference.
This is similar to the fix in commit 3027e7b15b02
("ice: Fix some null pointer dereference issues in ice_ptp.c").

This issue is found by our static analysis tool

Signed-off-by: Chenyuan Yang <chenyuan0y@gmail.com>
Link: https://lore.kernel.org/r/20250311012705.1233829-1-chenyuan0y@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>