lguest: avoid using NR_CPUS as a bounds check.

NR_CPUS (being a host number) is an arbitrary limit for the Guest.
Using the array size directly (which currently happes to be NR_CPUS)
is more futureproof.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
---
 drivers/lguest/lguest_user.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff -r 02d2848f1112 drivers/lguest/lguest_user.c
--- a/drivers/lguest/lguest_user.c	Thu Mar 20 17:54:36 2008 +1100
+++ b/drivers/lguest/lguest_user.c	Thu Mar 27 14:35:54 2008 +1100
@@ -97,6 +97,6 @@ static ssize_t read(struct file *file, c
 static int lg_cpu_start(struct lg_cpu *cpu, unsigned id, unsigned long start_ip)
 {
 	/* We have a limited number the number of CPUs in the lguest struct. */
-	if (id >= NR_CPUS)
+	if (id >= ARRAY_SIZE(cpu->lg->cpus))
 		return -EINVAL;