Add hack to flap macvlan dev if it already exists and if the route to

the vrr network is pointing to it

Ticket: CM-4639
Reviewed By:
Testing Done: Tested with interfaces file and steps from the bug

This is a Hack to make sure the primary address
is the first in the routing table. Its not a full proof solution.

We use `ip route get` on the vrr network to see which
device the kernel returns. if it is the mac vlan device,
flap the macvlan device to adjust the routing table entry.
flapping the macvlan device makes sure the macvlan
connected route goes through delete + add, hence adjusting
the order in the routing table.

ifupdownaddons/iproute2.py

@@ -685,3 +685,16 @@ class iproute2(utilsBase):
             ret = False
             pass
         return ret
+
+    def ip_route_get_dev(self, prefix):
+        try:
+            output = self.exec_command('ip route get %s' %prefix)
+            if output:
+               rline = output.splitlines()[0]
+               if rline:
+                    rattrs = rline.split()
+                    return rattrs[rattrs.index('dev') + 1]
+        except Exception, e:
+            self.logger.debug('ip_route_get_dev: failed .. %s' %str(e))
+            pass
+        return None