Bluetooth: Change simple_strtol to simple_strtoul

Since size, addr, fcs, and tmp are unsigned, it would seem better to use
simple_strtoul that simple_strtol.

A simplified version of the semantic patch that makes this change is as
follows: (http://www.emn.fr/x-info/coccinelle/

)

// <smpl>
@r2@
long e;
position p;
@@

e = simple_strtol@p(...)

@@
position p != r2.p;
type T;
T e;
@@

e =
- simple_strtol@p
+ simple_strtoul
  (...)
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>