staging: r8188eu: use pr_info_once() to log the firmware version

Use pr_info_once() instead of a static variable and an if statement
to log the firmware version only once.

Acked-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Michael Straube <straube.linux@gmail.com>
Link: https://lore.kernel.org/r/20220417175441.13830-8-straube.linux@gmail.com


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