ISDN/sc: fix longstanding warning

drivers/isdn/sc/shmem.c: In function 'memcpy_toshmem':
drivers/isdn/sc/shmem.c:54: warning: passing argument 1 of 'memcpy_toio' makes pointer from integer without a cast

Also, remove some unneeded braces, and add some useful whitespace.

Signed-off-by: Jeff Garzik <jgarzik@redhat.com>