bond: T7191: fix error message when member interface is used multiple times

Sharing the same physical interface among multiple bond interfaces causes
information to be lost within the error message

  set interfaces bonding bond10 member interface eth1
  set interfaces bonding bond10 member interface eth2
  set interfaces bonding bond20 member interface eth1
  set interfaces bonding bond20 member interface eth2
  commit

Results in:

[ interfaces bonding bond10 ]
Can not add interface "eth1" to bond, it is already a member of bond
"b"!

[[interfaces bonding bond10]] failed
[ interfaces bonding bond20 ]
Can not add interface "eth1" to bond, it is already a member of bond
"b"!

It should infact output the full name of the bond interface.

1 files changed, 10 insertions, 3 deletions

diff --git a/smoketest/scripts/cli/test_interfaces_bonding.py b/smoketest/scripts/cli/test_interfaces_bonding.py
index 1a72f9dc4..f99fd0363 100755
--- a/smoketest/scripts/cli/test_interfaces_bonding.py
+++ b/smoketest/scripts/cli/test_interfaces_bonding.py
@@ -167,18 +167,25 @@ class BondingInterfaceTest(BasicInterfaceTest.TestCase):
 
     def test_bonding_multi_use_member(self):
         # Define available bonding hash policies
-        for interface in ['bond10', 'bond20']:
+        bonds = ['bond10', 'bond20', 'bond30']
+        for interface in bonds:
             for member in self._members:
                 self.cli_set(self._base_path + [interface, 'member', 'interface', member])
 
         # check validate() - can not use the same member interfaces multiple times
         with self.assertRaises(ConfigSessionError):
             self.cli_commit()
-
-        self.cli_delete(self._base_path + ['bond20'])
+        # only keep the first bond interface configuration
+        for interface in bonds[1:]:
+            self.cli_delete(self._base_path + [interface])
 
         self.cli_commit()
 
+        bond = bonds[0]
+        member_ifaces = read_file(f'/sys/class/net/{bond}/bonding/slaves').split()
+        for member in self._members:
+            self.assertIn(member, member_ifaces)
+
     def test_bonding_source_interface(self):
         # Re-use member interface that is already a source-interface
         bond = 'bond99'