media: dvb_ca_en50221.h: fix checkpatch strict warnings

As we're already touching on dvb_ca_en50221 to cleanup
checkpatch issues, do that also for its header file, with:

	$ ./scripts/checkpatch.pl --strict --fix-inplace -f drivers/media/dvb-core/dvb_ca_en50221.h
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

drivers/media/dvb-core/dvb_ca_en50221.h

@@ -128,7 +128,7 @@ void dvb_ca_en50221_frda_irq(struct dvb_ca_en50221 *ca, int slot);
  *
  * @return 0 on success, nonzero on failure
  */
-extern int dvb_ca_en50221_init(struct dvb_adapter *dvb_adapter,
+int dvb_ca_en50221_init(struct dvb_adapter *dvb_adapter,
 			struct dvb_ca_en50221 *ca, int flags,
 			       int slot_count);
 
@@ -137,6 +137,6 @@ extern int dvb_ca_en50221_init(struct dvb_adapter *dvb_adapter,
  *
  * @ca: The associated dvb_ca instance.
  */
-extern void dvb_ca_en50221_release(struct dvb_ca_en50221 *ca);
+void dvb_ca_en50221_release(struct dvb_ca_en50221 *ca);
 
 #endif