[PATCH] docs: fix 'sample-pages' option tag

[huangy81]

From: Hyman Huang(黄勇) <huangy81@chinatelecom.cn>

commit f78d4ed701 has fixed qemu tag, making 'sample-pages' option tag
involved by accident, which introduced since 6.1 in commit 7afa08cd8fd.
revert this line.

Signed-off-by: Hyman Huang(黄勇) <huangy81@chinatelecom.cn>
---
 qapi/migration.json | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/qapi/migration.json b/qapi/migration.json
index f0aefda..bbfd48c 100644
--- a/qapi/migration.json
+++ b/qapi/migration.json
@@ -1796,7 +1796,7 @@
 # @calc-time: time in units of second for sample dirty pages
 #
 # @sample-pages: page count per GB for sample dirty pages
-#                the default value is 512 (since 6.2)
+#                the default value is 512 (since 6.1)
 #
 # @mode: mode containing method of calculate dirtyrate includes
 #        'page-sampling' and 'dirty-ring' (Since 6.2)
-- 
1.8.3.1