Update hwloc submodule to fix "make distcheck"

Hwloc upstream has fixed a problem with embedded "make distcheck" that
was breaking that surfaced when you ran autogen in an Open MPI
tarball.

This submodule update takes in the upstream hwloc fixes for this
issue.

Signed-off-by: Jeff Squyres <jsquyres@cisco.com>

opal/mca/hwloc/hwloc2/hwloc

@@ -1 +1 @@
-Subproject commit 38433c0f5fae0b761bd20e7b928c77f3ff2e76dc
+Subproject commit 4a43c39c89037f52b4e25927e58caf08f3707c33