largefiles: don't reference uninitialized variable (issue3092)

hgext/largefiles/lfcommands.py

@@ -237,7 +237,9 b' def _lfconvert_addchangeset(rsrc, rdst, '
             dstfiles.append(lfutil.standin(f))
             # largefile in manifest if it has not been removed/renamed
             if f in ctx.manifest():
-                if 'l' in ctx.filectx(f).flags():
+                fctx = ctx.filectx(f)
+                if 'l' in fctx.flags():
+                    renamed = fctx.renamed()
                     if renamed and renamed[0] in lfiles:
                         raise util.Abort(_('largefile %s becomes symlink') % f)