[PATCH v3] qapi/qom: Memory backend property prealloc-threads doc fix

[Zhenyu Zhang]

Commit ffac16fab3 "hostmem: introduce "prealloc-threads" property"
(v5.0.0) changed the default number of threads from number of CPUs
to 1.  This was deemed a regression, and fixed in commit f8d426a685
"hostmem: default the amount of prealloc-threads to smp-cpus".
Except the documentation remained unchanged.  Update it now.

Signed-off-by: Zhenyu Zhang <zhenyzha@redhat.com>
---

v3: Covers historical descriptions                  (Markus) 
v2: The property is changed to smp-cpus since 5.0   (Phild)

---
 qapi/qom.json | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/qapi/qom.json b/qapi/qom.json
index 30e76653ad..dfd89bc6d4 100644
--- a/qapi/qom.json
+++ b/qapi/qom.json
@@ -576,7 +576,7 @@
 #
 # @prealloc: if true, preallocate memory (default: false)
 #
-# @prealloc-threads: number of CPU threads to use for prealloc (default: 1)
+# @prealloc-threads: number of CPU threads to use for prealloc (default: 
number of CPUs) (since 5.0)
 #
 # @prealloc-context: thread context to use for creation of preallocation 
threads
 #                    (default: none) (since 7.2)
-- 
2.31.1