V4L/DVB: lgs8gxx: Use shifts rather than multiply/divide when possible

If val is a u64, then following:

	val *= (u64)1 << 32;
	val /= (u64)1 << 32;

should surely be better represented as:

	val <<= 32;
	val >>= 32;

Especially as, for the division, the compiler might want to actually do a
division:

drivers/built-in.o: In function `lgs8gxx_get_afc_phase':
drivers/media/dvb/frontends/lgs8gxx.c:250: undefined reference to `__udivdi3'
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/dvb/frontends/lgs8gxx.c

@@ -199,7 +199,7 @@ static int lgs8gxx_set_if_freq(struct lgs8gxx_state *priv, u32 freq /*in kHz*/)
 
 	val = freq;
 	if (freq != 0) {
-		val *= (u64)1 << 32;
+		val <<= 32;
 		if (if_clk != 0)
 			do_div(val, if_clk);
 		v32 = val & 0xFFFFFFFF;
@@ -246,7 +246,7 @@ static int lgs8gxx_get_afc_phase(struct lgs8gxx_state *priv)
 
 	val = v32;
 	val *= priv->config->if_clk_freq;
-	val /= (u64)1 << 32;
+	val >>= 32;
 	dprintk("AFC = %u kHz\n", (u32)val);
 	return 0;
 }