[media] v4l2-common: h_bp var is unused at v4l2_detect_gtf()

		struct v4l2_dv_timings *fmt)

{

	int pix_clk;

	int  v_fp, v_bp, h_fp, h_bp, hsync;

	int  v_fp, v_bp, h_fp, hsync;

	int frame_width, image_height, image_width;

	bool default_gtf;

	int h_blank;

	hsync = hsync - hsync % GTF_CELL_GRAN;

	h_fp = h_blank / 2 - hsync;

	h_bp = h_blank / 2;

	fmt->bt.polarities = polarities;

	fmt->bt.width = image_width;