[PATCH] USBATM: fix modinfo output

Because of the way stringify works, using an expression
like 64 * 1024 for UDSL_MAX_BUF_SIZE results in 64 * 1024
turning up in the modinfo output instead of 65536.  So use
65536 directly (this was the only way I found of fixing this).

Signed-off-by: Duncan Sands <baldrick@free.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>