arch/x86/kernel/pci-calgary_64.c: change simple_strtol to simple_strtoul

Impact: fix theoretical option string parsing overflow

Since bridge is 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: NJulia Lawall <julia@diku.dk>
Cc: muli@il.ibm.com
Cc: jdmason@kudzu.us
Cc: discuss@x86-64.org
Signed-off-by: NIngo Molnar <mingo@elte.hu>

arch/x86/kernel/pci-calgary_64.c

@@ -1567,7 +1567,7 @@ static int __init calgary_parse_options(char *p)
 				++p;
 			if (*p == '\0')
 				break;
-			bridge = simple_strtol(p, &endp, 0);
+			bridge = simple_strtoul(p, &endp, 0);
 			if (p == endp)
 				break;