[media] r820t: quiet gcc warning on n_ring

drivers/media/tuners/r820t.c: In function 'r820t_imr':
 drivers/media/tuners/r820t.c:1871:8: warning: 'n_ring' may be used uninitialized in this function [-Wmaybe-uninitialized]
Mauro: This is a FALSE POSITIVE: the loop will always return a value
for n_ring, as the last test will fill it with 15, if the loop fails.

Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/tuners/r820t.c

@@ -1854,15 +1854,12 @@ static int r820t_imr(struct r820t_priv *priv, unsigned imr_mem, bool im_flag)
 	else
 		ring_ref = priv->cfg->xtal;
 
+	n_ring = 15;
 	for (n = 0; n < 16; n++) {
 		if ((16 + n) * 8 * ring_ref >= 3100000) {
 			n_ring = n;
 			break;
 		}
-
-		/* n_ring not found */
-		if (n == 15)
-			n_ring = n;
 	}
 
 	reg18 = r820t_read_cache_reg(priv, 0x18);