gpib: Fix memory leak in ni_usb_init()

In the Linux kernel, the following vulnerability has been resolved:

gpib: Fix memory leak in ni_usb_init()

In ni_usb_init(), if ni_usb_setup_init() fails, the function returns

-EFAULT without freeing the allocated writes buffer, leading to a

memory leak.

Additionally, ni_usb_setup_init() returns 0 on failure, which causes

ni_usb_init() to return -EFAULT, an inappropriate error code for this

situation.

Fix the leak by freeing writes in the error path. Modify

ni_usb_setup_init() to return -EINVAL on failure and propagate this

error code in ni_usb_init().