parport: "dev->timeslice" is an unsigned long, not an int

While auditing proc_doulongvec_ms_jiffies_minmax() usage in kernel, I found
a bug in drivers/parport/procfs.c, incorrectly using sizeof(int) instead of
sizeof(unsigned long)

Only 64bit arches are affected by this old bug.

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>