V4L/DVB: dib0090: cleanup dib0090_dcc_freq()

'extern' is not needed at function definition.

This will remove the following sparse warning (see "make C=1"):
 * function 'dib0090_dcc_freq' with external linkage has definition
Signed-off-by: Márton Németh <nm127@freemail.hu>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/dvb/frontends/dib0090.c

@@ -283,7 +283,7 @@ static int dib0090_sleep(struct dvb_frontend *fe)
 	return 0;
 }
 
-extern void dib0090_dcc_freq(struct dvb_frontend *fe, u8 fast)
+void dib0090_dcc_freq(struct dvb_frontend *fe, u8 fast)
 {
 	struct dib0090_state *state = fe->tuner_priv;
 	if (fast)