Encoding: drop struct gprs_rlcmac_bts* from all functions

The bts is not used at all.

Change-Id: Ia07755e825913a16352ab13f6cf55f2918de8681
diff --git a/src/encoding.h b/src/encoding.h
index 2309dc3..6dcced0 100644
--- a/src/encoding.h
+++ b/src/encoding.h
@@ -27,7 +27,6 @@
 #include <osmocom/gsm/l1sap.h>
 }
 
-struct gprs_rlcmac_bts;
 struct gprs_rlcmac_tbf;
 struct bitvec;
 struct gprs_llc;
@@ -57,7 +56,6 @@
 		);
 
 	static void write_packet_uplink_assignment(
-			struct gprs_rlcmac_bts *bts,
 			bitvec * dest, uint8_t old_tfi,
 			uint8_t old_downlink, uint32_t tlli, uint8_t use_tlli,
 			struct gprs_rlcmac_ul_tbf *tbf, uint8_t poll, uint8_t rrbp,
@@ -76,8 +74,7 @@
 		bitvec * dest, uint32_t tlli);
 
 	static void write_packet_uplink_ack(
-			struct gprs_rlcmac_bts *bts, bitvec * dest,
-			struct gprs_rlcmac_ul_tbf *tbf, bool is_final,
+			bitvec * dest, struct gprs_rlcmac_ul_tbf *tbf, bool is_final,
 			uint8_t rrbp);
 
 	static int write_paging_request(bitvec * dest, uint8_t *ptmsi, uint16_t ptmsi_len);