hysdn: Remove cli()/sti() calls.

The use of cli()/sti() within the do/while was a way to ensure
interrupts were only disabled for short periods of time while the bulk
of the time interrupts were free to occur.  The use of the spin lock
has eliminated the need to play with interrupts in this way while
still allowing for IO to be protected.

The remaining 3 sti() calls seem unneeded now that at no other point
in the driver is there a call to cli().

Signed-off-by: Mark Asselstine <mark.asselstine@windriver.com>
Acked-by: Karsten Keil <kkeil@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>