fixing path for ubuntu

this path exists on centos7 and ubuntu. ubuntu currently keeps installing the driver everytime I run the role

roles/mellanox_drivers/tasks/main.yml

@@ -101,7 +101,7 @@
 
 - name: test for existing installation of drivers
   stat:
-    path: /bin/ibv_devinfo
+    path: /usr/bin/ibv_devinfo
   become: true
   register: drivers_installed