build/ops: bump rocksdb submodule

Fixes a FTBFS on ppc64le

Fixes: http://tracker.ceph.com/issues/17092
Signed-off-by: Nathan Cutler <ncutler@suse.com>

diff --git a/src/rocksdb b/src/rocksdb
index fa98456ccbd860120127ac2e91a2088fb222606e..92749e88f5d9c8dc6e6aba1ff297f21f1e7ea811 160000 (submodule)
--- a/src/rocksdb
+++ b/src/rocksdb
@@ -1 +1 @@
-Subproject commit fa98456ccbd860120127ac2e91a2088fb222606e
+Subproject commit 92749e88f5d9c8dc6e6aba1ff297f21f1e7ea811