[gnome-settings-daemon] common: Drop an unused static function

[Philip Withnall <pwithnall src gnome org>]

commit 76c80d09fedaa40cdffeb19b0639d1c083eb8a23
Author: Philip Withnall <withnall endlessm com>
Date:   Fri Oct 13 13:08:47 2017 +0100

    common: Drop an unused static function
    
    The last call site to it was dropped in commit 4db56864; this just fixes
    a compiler warning about the unused function.
    
    Signed-off-by: Philip Withnall <withnall endlessm com>
    
    https://bugzilla.gnome.org/show_bug.cgi?id=788933

 plugins/common/gsd-device-mapper.c |   27 ---------------------------
 1 files changed, 0 insertions(+), 27 deletions(-)
---
diff --git a/plugins/common/gsd-device-mapper.c b/plugins/common/gsd-device-mapper.c
index 6894557..c9a113c 100644
--- a/plugins/common/gsd-device-mapper.c
+++ b/plugins/common/gsd-device-mapper.c
@@ -187,33 +187,6 @@ find_builtin_output (GnomeRRScreen *rr_screen)
        return NULL;
 }
 
-static GnomeRROutput *
-monitor_to_output (GsdDeviceMapper *mapper,
-                  gint             monitor_num)
-{
-       GnomeRROutput **outputs;
-       guint i;
-
-       g_return_val_if_fail (mapper->rr_screen != NULL, NULL);
-
-       outputs = gnome_rr_screen_list_outputs (mapper->rr_screen);
-
-       for (i = 0; outputs[i] != NULL; i++) {
-               GnomeRRCrtc *crtc = gnome_rr_output_get_crtc (outputs[i]);
-               gint x, y;
-
-               if (!crtc)
-                       continue;
-
-               gnome_rr_crtc_get_position (crtc, &x, &y);
-
-               if (monitor_num == gdk_screen_get_monitor_at_point (mapper->screen, x, y))
-                       return outputs[i];
-       }
-
-       return NULL;
-}
-
 static MappingHelper *
 mapping_helper_new (void)
 {