profiling: fix broken profiling regression

Impact: fix broken /proc/profile on UP machines

Commit c309b917cab55799ea489d7b5f1b77025d9f8462 "cpumask: convert
kernel/profile.c" broke profiling.  prof_cpu_mask was previously
initialized to CPU_MASK_ALL, but left uninitialized in that commit.
We need to copy cpu_possible_mask (cpu_online_mask is not enough).

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/profile.c b/kernel/profile.c
index 784933ac..7724e04 100644
--- a/kernel/profile.c
+++ b/kernel/profile.c
@@ -114,12 +114,15 @@
 	if (!slab_is_available()) {
 		prof_buffer = alloc_bootmem(buffer_bytes);
 		alloc_bootmem_cpumask_var(&prof_cpu_mask);
+		cpumask_copy(prof_cpu_mask, cpu_possible_mask);
 		return 0;
 	}
 
 	if (!alloc_cpumask_var(&prof_cpu_mask, GFP_KERNEL))
 		return -ENOMEM;
 
+	cpumask_copy(prof_cpu_mask, cpu_possible_mask);
+
 	prof_buffer = kzalloc(buffer_bytes, GFP_KERNEL);
 	if (prof_buffer)
 		return 0;