staging: gpib: Modify gpib_register_driver() to return error if it fails

staging: gpib: Modify gpib_register_driver() to return error if it fails

The function gpib_register_driver() can fail if kmalloc() fails,
but it doesn't return any error if that happens.

Modify the function to return error i.e int. Return the appropriate
error code if it fails. Remove the pr_info() statement.

Signed-off-by: Nihar Chaithanya <niharchaithanya@gmail.com>
Link: https://lore.kernel.org/r/20241230185633.175690-2-niharchaithanya@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>