wakeonlan: Improve module coverage (#26655)

Trying to get this to 100% !

test/integration/targets/wakeonlan/tasks/main.yml

@@ -7,3 +7,42 @@
   wakeonlan:
     mac: 00-00-5E-00-53-66
     port: 9
+
+- name: Provide an incorrect MAC length
+  wakeonlan:
+    mac: 00-00-5E-00-53-66-AB
+    port: 9
+  ignore_errors: yes
+  register: incorrect_mac_length
+
+- name: Check error message
+  assert:
+    that:
+    - incorrect_mac_length|failed
+    - incorrect_mac_length.msg is search('Incorrect MAC address length')
+
+- name: Provide an incorrect MAC format
+  wakeonlan:
+    mac: ZW-YX-WV-UT-SR-QP
+    port: 9
+  ignore_errors: yes
+  register: incorrect_mac_format
+
+- name: Check error message
+  assert:
+    that:
+    - incorrect_mac_format|failed
+    - incorrect_mac_format.msg is search('Incorrect MAC address format')
+
+- name: Cause a socket error
+  wakeonlan:
+    mac: 00-00-5E-00-53-66
+    broadcast: 345.567.678.890
+  ignore_errors: yes
+  register: incorrect_broadcast_address
+
+- name: Check error message
+  assert:
+    that:
+    - incorrect_broadcast_address|failed
+    - incorrect_broadcast_address.msg is search('not known')