demo: remove workarounds that have been upstreamed to nemu

Nemu previously had an issue with PIDs above 4 hex digits (> 65535) where created network interfaces would have names of length exceeding IFNAMSIZ. These fixes have been upstreamed in nemu3.

demo/fixnemu.py

@@ -71,19 +71,3 @@ def _get_addr_data():
     byidx, bynam = get_addr_data.orig()
     return byidx, {name.split('@',1)[0]: a for name, a in bynam.items()}
 get_addr_data.__code__ = _get_addr_data.__code__
-
-@staticmethod
-def _gen_if_name():
-    n = Interface._gen_next_id()
-    # Max 15 chars
-    # XXX: We truncate pid to not exceed IFNAMSIZ on systems with 32-bits pids
-    #      but we should find something better to avoid possible collision.
-    return "NETNSif-%.4x%.3x" % (os.getpid() % 0xffff, n)
-Interface._gen_if_name = _gen_if_name
-
-@staticmethod
-def _gen_br_name():
-    n = Switch._gen_next_id()
-     # XXX: same as for _gen_if_name
-    return "NETNSbr-%.4x%.3x" % (os.getpid() % 0xffff, n)
-Switch._gen_br_name = _gen_br_name