drx-j: use ber_count var

drivers/media/dvb-frontends/drx39xyj/drxj.c: In function 'ctrl_get_qam_sig_quality':
drivers/media/dvb-frontends/drx39xyj/drxj.c:9468:6: warning: variable 'ber_cnt' set but not used [-Wunused-but-set-variable]
  u32 ber_cnt = 0; /* BER count */
      ^

By reading the comment, it is said that BER should be calculated as:
	qam_pre_rs_ber = frac_times1e6( ber_cnt, rs_bit_cnt );

Also, it makes sense to take the mantissa into account, so fix the
code to do what's commented.
Signed-off-by: NMauro Carvalho Chehab <m.chehab@samsung.com>

drivers/media/dvb-frontends/drx39xyj/drxj.c

@@ -9583,7 +9583,7 @@ ctrl_get_qam_sig_quality(struct drx_demod_instance *demod)
 	if (m > (rs_bit_cnt >> (e + 1)) || (rs_bit_cnt >> e) == 0)
 		qam_pre_rs_ber = 500000 * rs_bit_cnt >> e;
 	else
-		qam_pre_rs_ber = m;
+		qam_pre_rs_ber = ber_cnt;
 
 	/* post RS BER = 1000000* (11.17 * FEC_OC_SNC_FAIL_COUNT__A) /  */
 	/*               (1504.0 * FEC_OC_SNC_FAIL_PERIOD__A)  */