[tracker] libtracker-remote: Fix compiler warning

[Carlos Garnacho <carlosg src gnome org>]

commit f49529d45a29121420b1a2f19c6e125add4464fb
Author: Carlos Garnacho <carlosg gnome org>
Date:   Sun Sep 10 00:01:23 2017 +0200

    libtracker-remote: Fix compiler warning
    
    The return value of the hashtable contents are not variable, so using
    "var" rightfully complains about const being passed to non-const.

 src/libtracker-remote/tracker-xml-cursor.vala |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/src/libtracker-remote/tracker-xml-cursor.vala b/src/libtracker-remote/tracker-xml-cursor.vala
index de0e51a..ef7349e 100644
--- a/src/libtracker-remote/tracker-xml-cursor.vala
+++ b/src/libtracker-remote/tracker-xml-cursor.vala
@@ -104,7 +104,7 @@ public class Tracker.Remote.XmlCursor : Tracker.Sparql.Cursor {
 
        public override Sparql.ValueType get_value_type (int column) requires (_cur_row != null) {
                var variable = _vars[column];
-               var node = _cur_row_map.get (variable);
+               Xml.Node* node = (Xml.Node*) _cur_row_map.get (variable);
                if (node == null)
                        return Sparql.ValueType.UNBOUND;
 
@@ -147,7 +147,7 @@ public class Tracker.Remote.XmlCursor : Tracker.Sparql.Cursor {
                length = 0;
 
                var variable = _vars[column];
-               var node = _cur_row_map.get (variable);
+               Xml.Node* node = (Xml.Node*) _cur_row_map.get (variable);
                if (node == null)
                        return null;