scmutil.addremove: remove redundant directory and symlink checks

scmutil.addremove: remove redundant directory and symlink checks

dirstate.walk only does lstats and never returns stat objects for directories.

On a large repository with 170,000 files, this speeds perfaddremove up from
2.40 seconds to 2.34.

--- a/mercurial/scmutil.py	Tue Apr 02 14:46:55 2013 -0700
+++ b/mercurial/scmutil.py	Tue Apr 02 14:49:34 2013 -0700
@@ -686,8 +686,7 @@
             if repo.ui.verbose or not m.exact(abs):
                 rel = m.rel(abs)
                 repo.ui.status(_('adding %s\n') % ((pats and rel) or abs))
-        elif (dstate != 'r' and (not st or
-               (stat.S_ISDIR(st.st_mode) and not stat.S_ISLNK(st.st_mode)))):
+        elif dstate != 'r' and not st:
             deleted.append(abs)
             if repo.ui.verbose or not m.exact(abs):
                 rel = m.rel(abs)