readmarkers: drop a conditional

mercurial/obsolete.py

@@ -302,9 +302,7 def _fm1readmarkers(data, off=0):
             _fm1node = _fm1nodesha256
             fnodesize = _fm1nodesha256size
 
-        # read replacement
-        sucs = ()
-        if numsuc:
+        # read 0 or more successors
             s = (fnodesize * numsuc)
             sucs = _unpack(_fm1node * numsuc, data[off:off + s])
             off += s