rocksdb: update to 3.11.2

Signed-off-by: Sage Weil <sage@redhat.com>

diff --git a/src/rocksdb b/src/rocksdb
index e0ab03a46bed911ec7b8d8506b2c62322d128b49..f371049d895a083810746a00049688043d8cea7e 160000 (submodule)
--- a/src/rocksdb
+++ b/src/rocksdb
@@ -1 +1 @@
-Subproject commit e0ab03a46bed911ec7b8d8506b2c62322d128b49
+Subproject commit f371049d895a083810746a00049688043d8cea7e