powerpc: Fix debug print in smp_setup_cpu_maps

When figuring out the number of threads, the debug message prints "1
thread" for the first iteration of the loop, instead of the actual
number of threads calculated from the length of the
"ibm,ppc-interrupt-server#s" property.

  * /cpus/PowerPC,POWER8@20...
    ibm,ppc-interrupt-server#s -> 1 threads <--- WRONG
    thread 0 -> cpu 0 (hard id 32)
    thread 1 -> cpu 1 (hard id 33)
    thread 2 -> cpu 2 (hard id 34)
    thread 3 -> cpu 3 (hard id 35)
    thread 4 -> cpu 4 (hard id 36)
    thread 5 -> cpu 5 (hard id 37)
    thread 6 -> cpu 6 (hard id 38)
    thread 7 -> cpu 7 (hard id 39)
  * /cpus/PowerPC,POWER8@28...
    ibm,ppc-interrupt-server#s -> 8 threads
    thread 0 -> cpu 8 (hard id 40)
    thread 1 -> cpu 9 (hard id 41)
    thread 2 -> cpu 10 (hard id 42)
    thread 3 -> cpu 11 (hard id 43)
    thread 4 -> cpu 12 (hard id 44)
    thread 5 -> cpu 13 (hard id 45)
    thread 6 -> cpu 14 (hard id 46)
    thread 7 -> cpu 15 (hard id 47)
(...)
Signed-off-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210120181847.952106-1-farosas@linux.ibm.com

arch/powerpc/kernel/setup-common.c

@@ -456,8 +456,8 @@ void __init smp_setup_cpu_maps(void)
 		intserv = of_get_property(dn, "ibm,ppc-interrupt-server#s",
 				&len);
 		if (intserv) {
-			DBG("    ibm,ppc-interrupt-server#s -> %d threads\n",
-			    nthreads);
+			DBG("    ibm,ppc-interrupt-server#s -> %lu threads\n",
+			    (len / sizeof(int)));
 		} else {
 			DBG("    no ibm,ppc-interrupt-server#s -> 1 thread\n");
 			intserv = of_get_property(dn, "reg", &len);