[mutter] screen-cast/src: Use G_USEC_PER_SEC instead of 1000000

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit 50634d450ecd826e5b51afa520bbcabf7f54c692
Author: Jonas Ådahl <jadahl gmail com>
Date:   Wed Jul 8 15:08:23 2020 +0200

    screen-cast/src: Use G_USEC_PER_SEC instead of 1000000
    
    https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1361

 src/backends/meta-screen-cast-stream-src.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)
---
diff --git a/src/backends/meta-screen-cast-stream-src.c b/src/backends/meta-screen-cast-stream-src.c
index 6a94ce600a..74df526db2 100644
--- a/src/backends/meta-screen-cast-stream-src.c
+++ b/src/backends/meta-screen-cast-stream-src.c
@@ -509,8 +509,9 @@ meta_screen_cast_stream_src_maybe_record_frame (MetaScreenCastStreamSrc  *src,
       int64_t min_interval_us;
       int64_t time_since_last_frame_us;
 
-      min_interval_us = ((1000000 * priv->video_format.max_framerate.denom) /
-                         priv->video_format.max_framerate.num);
+      min_interval_us =
+        ((G_USEC_PER_SEC * priv->video_format.max_framerate.denom) /
+         priv->video_format.max_framerate.num);
 
       time_since_last_frame_us = now_us - priv->last_frame_timestamp_us;
       if (time_since_last_frame_us < min_interval_us)