encoding: use bool for use_egprs in write_packet_uplink_assignment()

Change-Id: Iab4fb44c666a0d4fe8c98f5ff9221e23a6f1f2fa
diff --git a/src/encoding.cpp b/src/encoding.cpp
index 6a60485..15de6d7 100644
--- a/src/encoding.cpp
+++ b/src/encoding.cpp
@@ -539,7 +539,7 @@
 	bitvec * dest, uint8_t old_tfi,
 	uint8_t old_downlink, uint32_t tlli, uint8_t use_tlli,
 	const struct gprs_rlcmac_ul_tbf *tbf, uint8_t poll, uint8_t rrbp, uint8_t alpha,
-	uint8_t gamma, int8_t ta_idx, int8_t use_egprs)
+	uint8_t gamma, int8_t ta_idx, bool use_egprs)
 {
 	// TODO We should use our implementation of encode RLC/MAC Control messages.
 	unsigned wp = 0;
diff --git a/src/encoding.h b/src/encoding.h
index 525f8e6..a556687 100644
--- a/src/encoding.h
+++ b/src/encoding.h
@@ -61,7 +61,7 @@
 			uint8_t old_downlink, uint32_t tlli, uint8_t use_tlli,
 			const struct gprs_rlcmac_ul_tbf *tbf, uint8_t poll, uint8_t rrbp,
 			uint8_t alpha, uint8_t gamma, int8_t ta_idx,
-			int8_t use_egprs);
+			bool use_egprs);
 
 	static void write_packet_downlink_assignment(RlcMacDownlink_t * block,
 			bool old_tfi_is_valid, uint8_t old_tfi, uint8_t old_downlink,