ipaautomountmap: Force setting automountmapname in IPA API calls.

The usage of 'automountmapname' is required in all automount map IPA
API calls, and this change ensures that the value is always set as
an argument.

plugins/modules/ipaautomountmap.py

@@ -123,9 +123,10 @@ class AutomountMap(IPAAnsibleModule):
         self.params_fail_used_invalid(invalid, state)
 
     def get_args(self, mapname, desc):  # pylint: disable=no-self-use
-        _args = {}
-        if mapname:
-            _args["automountmapname"] = mapname
+        # automountmapname is required for all automountmap operations.
+        if not mapname:
+            self.fail_json(msg="automountmapname cannot be None or empty.")
+        _args = {"automountmapname": mapname}
         # An empty string is valid and will clear the attribute.
         if desc is not None:
             _args["description"] = desc