MFC r233193:

MFC r233193:

Add explicit braces to avoid dangling else in stl_tree.h.  This silences
the following warning produced by clang trunk:

  In file included from /usr/src/sbin/devd/devd.cc:91:
  In file included from /usr/obj/usr/src/tmp/usr/include/c++/4.2/map:64:
  /usr/obj/usr/src/tmp/usr/include/c++/4.2/bits/stl_tree.h:987:2: error: add explicit braces to avoid dangling else [-Werror,-Wdangling-else]
        else
        ^

git-svn-id: svn://svn.freebsd.org/base/stable/9@233297 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f