gprs: use new uint8_t * for kv in gprs_cipher_run()

libosmocore changed in bf990bb8 Update internal GPRS cipher API
from uint_64 to uint8_t*.
Fix a warning.

Change-Id: Ib5bfe1fb05c693347b11ff4faadd3fc2205ebd76
diff --git a/openbsc/src/gprs/gprs_llc.c b/openbsc/src/gprs/gprs_llc.c
index 4cf5163..883f0cc 100644
--- a/openbsc/src/gprs/gprs_llc.c
+++ b/openbsc/src/gprs/gprs_llc.c
@@ -410,7 +410,7 @@
 		uint8_t cipher_out[GSM0464_CIPH_MAX_BLOCK];
 		uint32_t iv;
 		int rc, i;
-		uint64_t kc = *(uint64_t *)&lle->llme->kc;
+		uint8_t *kc = lle->llme->kc;
 
 		/* Compute the 'Input' Paraemeter */
 		iv = gprs_cipher_gen_input_ui(iov_ui, sapi, nu, oc);
@@ -611,7 +611,7 @@
 		uint16_t crypt_len = llhp.data_len + 3;
 		uint8_t cipher_out[GSM0464_CIPH_MAX_BLOCK];
 		uint32_t iv;
-		uint64_t kc = *(uint64_t *)&lle->llme->kc;
+		uint8_t *kc = lle->llme->kc;
 		int rc, i;
 
 		if (lle->llme->algo == GPRS_ALGO_GEA0) {