[media] dib8000: Fix a few warnings when compiled for avr32

drivers/media/dvb-frontends/dib8000.c: In function 'dib8000_get_time_us':
drivers/media/dvb-frontends/dib8000.c:3957: warning: 'interleaving' may be used uninitialized in this function
drivers/media/dvb-frontends/dib8000.c:3956: warning: 'rate_denum' may be used uninitialized in this function

Those are actually false positives, but it doesn't hurt cleaning them.

Signed-off-by: Mauro Carvalho Chehab <[e-mail]>

drivers/media/dvb-frontends/dib8000.c

···
 	int ini_layer, end_layer, i;
 	u64 time_us, tmp64;
 	u32 tmp, denom;
-	int guard, rate_num, rate_denum, bits_per_symbol, nsegs;
-	int interleaving, fft_div;
+	int guard, rate_num, rate_denum = 1, bits_per_symbol, nsegs;
+	int interleaving = 0, fft_div;
 
 	if (layer >= 0) {
 		ini_layer = layer;