usb: gadget: u_audio: convert to strscpy

Usage of strlcpy in Linux Kernel has been recently
deprecated [1], convert driver to strscpy

[1] https://lore.kernel.org/lkml/CAHk-=wgfRnXz0W3D37d01q3JFkr_i_uTL=V6A6G1oUZcprmknw@mail.gmail.com/



Signed-off-by: Ruslan Bilovol <ruslan.bilovol@gmail.com>
Link: https://lore.kernel.org/r/1614603943-11668-2-git-send-email-ruslan.bilovol@gmail.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>