[S390] appldata: avoid deadlock with appldata_mem

The appldata_ops callbacks are called with a spin_lock held. But the
appldata_mem callback then calls all_vm_events(), which calls
get_online_cpus(), which might sleep. This possible deadlock is fixed
by using a mutex instead of a spin_lock.

Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/appldata/appldata_mem.c b/arch/s390/appldata/appldata_mem.c
index 3ed56b7..4188cbe 100644
--- a/arch/s390/appldata/appldata_mem.c
+++ b/arch/s390/appldata/appldata_mem.c
@@ -78,7 +78,7 @@
 {
 	/*
 	 * don't put large structures on the stack, we are
-	 * serialized through the appldata_ops_lock and can use static
+	 * serialized through the appldata_ops_mutex and can use static
 	 */
 	static struct sysinfo val;
 	unsigned long ev[NR_VM_EVENT_ITEMS];