agp: remove unused variable num_segments

This patch fix the following build warning:
warning: variable 'num_segments' set but not used [-Wunused-but-set-variable]
Signed-off-by: Corentin Labbe <clabbe@baylibre.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1574324085-4338-4-git-send-email-clabbe@baylibre.com

drivers/char/agp/frontend.c

@@ -102,14 +102,13 @@ agp_segment_priv *agp_find_seg_in_client(const struct agp_client *client,
 					    int size, pgprot_t page_prot)
 {
 	struct agp_segment_priv *seg;
-	int num_segments, i;
+	int i;
 	off_t pg_start;
 	size_t pg_count;
 
 	pg_start = offset / 4096;
 	pg_count = size / 4096;
 	seg = *(client->segments);
-	num_segments = client->num_segments;
 
 	for (i = 0; i < client->num_segments; i++) {
 		if ((seg[i].pg_start == pg_start) &&