libnvme: git submodule update

Pull in changes to fixup endless loop during discovery.

diff --git a/libnvme b/libnvme
index 278aba093e64bb89d8e471ddf1d0c83b0ff5b2f5..8654fc792e73657a0115323ed94eaf735c6f3bbe 160000 (submodule)
--- a/libnvme
+++ b/libnvme
@@ -1 +1 @@
-Subproject commit 278aba093e64bb89d8e471ddf1d0c83b0ff5b2f5
+Subproject commit 8654fc792e73657a0115323ed94eaf735c6f3bbe