Remove return from supports block

Part of ManageIQ/manageiq#22898 (as a followup)

Introduced by ManageIQ#659

You can not have a return in a block. It causes a LongJump error
Besides, it tries to return from inside the calling block - not what we want.

Fixes a missed unsupported reason check

app/models/manageiq/providers/ovirt/infra_manager/host.rb

@@ -12,13 +12,19 @@ def provider_object(connection = nil)
   end
 
   supports :enter_maint_mode do
-    return _('The Host is not connected to an active provider') unless has_active_ems?
-    return _('The Host is not powered on') unless power_state == 'on'
+    if !has_active_ems?
+      _('The Host is not connected to an active provider')
+    elsif power_state != 'on'
+      _('The Host is not powered on')
+    end
   end
 
   supports :exit_maint_mode do
-    _('The Host is not connected to an active provider') unless has_active_ems?
-    _('The Host is not in maintenance mode') unless power_state == 'maintenance'
+    if !has_active_ems?
+      _('The Host is not connected to an active provider')
+    elsif power_state != 'maintenance'
+      _('The Host is not in maintenance mode')
+    end
   end
 
   def enter_maint_mode