[IA64] make pfm_get_task work with virtual pids

This pid comes from user space, so treat it accordingly.
Signed-off-by: NPavel Emelyanov <xemul@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NTony Luck <tony.luck@intel.com>

arch/ia64/kernel/perfmon.c

@@ -2654,11 +2654,11 @@ pfm_get_task(pfm_context_t *ctx, pid_t pid, struct task_struct **task)
 	/* XXX: need to add more checks here */
 	if (pid < 2) return -EPERM;
 
-	if (pid != current->pid) {
+	if (pid != task_pid_vnr(current)) {
 
 		read_lock(&tasklist_lock);
 
-		p = find_task_by_pid(pid);
+		p = find_task_by_vpid(pid);
 
 		/* make sure task cannot go away while we operate on it */
 		if (p) get_task_struct(p);