staging: gpib: use proper format string in request_module

staging: gpib: use proper format string in request_module

Using a string variable as a format causes a -Wformat-security
warning. Since the only use of the temporary module_string[] is to hold
the sprintf() output, just pass the format string and argument directly
to request_module().

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20241016111521.1143191-7-arnd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>