pcu_l1_if: cosmetic: use sizeof instead of constants

Change-Id: Ib99e0a5470758bc4235b140103f2abd448ac07d3
diff --git a/src/pcu_l1_if.cpp b/src/pcu_l1_if.cpp
index 810ce85..15ae94f 100644
--- a/src/pcu_l1_if.cpp
+++ b/src/pcu_l1_if.cpp
@@ -273,7 +273,7 @@
 	if (the_pcu->gsmtap_categ_mask & (1 << PCU_GSMTAP_C_DL_AGCH))
 		gsmtap_send(the_pcu->gsmtap, 0, 0, GSMTAP_CHANNEL_AGCH, 0, 0, 0, 0, data, GSM_MACBLOCK_LEN);
 
-	pcu_tx_data_req(bts, 0, 0, PCU_IF_SAPI_AGCH, 0, 0, 0, data, GSM_MACBLOCK_LEN);
+	pcu_tx_data_req(bts, 0, 0, PCU_IF_SAPI_AGCH, 0, 0, 0, data, sizeof(data));
 }
 
 void pcu_l1if_tx_pch(struct gprs_rlcmac_bts *bts, bitvec * block, int plen, uint16_t pgroup)
@@ -298,7 +298,7 @@
 	if (the_pcu->gsmtap_categ_mask & (1 << PCU_GSMTAP_C_DL_PCH))
 		gsmtap_send(the_pcu->gsmtap, 0, 0, GSMTAP_CHANNEL_PCH, 0, 0, 0, 0, data + 3, GSM_MACBLOCK_LEN);
 
-	pcu_tx_data_req(bts, 0, 0, PCU_IF_SAPI_PCH, 0, 0, 0, data, PAGING_GROUP_LEN + GSM_MACBLOCK_LEN);
+	pcu_tx_data_req(bts, 0, 0, PCU_IF_SAPI_PCH, 0, 0, 0, data, sizeof(data));
 }
 
 int pcu_tx_neigh_addr_res_req(struct gprs_rlcmac_bts *bts, const struct neigh_cache_entry_key *neigh_key)