[mutter] kms/connector: Use utility function to get the property ID

[Marge Bot <marge-bot src gnome org>]

commit 3d689989ea80853427a66e1906f168bb9d4a2f47
Author: Marco Trevisan (Treviño) <mail 3v1n0 net>
Date:   Mon Mar 22 00:45:20 2021 +0100

    kms/connector: Use utility function to get the property ID
    
    We already have one for this, so use it instead of repeating the same
    
    Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1964>

 src/backends/native/meta-kms-connector.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
---
diff --git a/src/backends/native/meta-kms-connector.c b/src/backends/native/meta-kms-connector.c
index 01b5720190..5121dc94d8 100644
--- a/src/backends/native/meta-kms-connector.c
+++ b/src/backends/native/meta-kms-connector.c
@@ -126,7 +126,8 @@ meta_kms_connector_is_underscanning_supported (MetaKmsConnector *connector)
   uint32_t underscan_prop_id;
 
   underscan_prop_id =
-    connector->prop_table.props[META_KMS_CONNECTOR_PROP_UNDERSCAN].prop_id;
+    meta_kms_connector_get_prop_id (connector,
+                                    META_KMS_CONNECTOR_PROP_UNDERSCAN);
 
   return underscan_prop_id != 0;
 }