Uninitialized variable in ipa_ccm_make_id_resp_from_req()

We are allocating a buffer on the stack without initializing it, and
then passing it into ipa_ccm_make_id_resp().  There is no real danger
from this, as the buffer is only uninitialized if num_ies is 0, but
let's memset() it for good style

Change-Id: If5761a47b8cba73ddcc02a88cfa5c87c1970c04e
Fixes: coverity CID#167040
diff --git a/src/gsm/ipa.c b/src/gsm/ipa.c
index 01bd0c5..2c0880a 100644
--- a/src/gsm/ipa.c
+++ b/src/gsm/ipa.c
@@ -302,6 +302,8 @@
 	unsigned int num_ies = 0;
 	const uint8_t *cur = data;
 
+	memset(ies, 0, sizeof(ies));
+
 	/* build a array of the IEIs */
 	while (len >= 2) {
 		uint8_t t_len, t_tag;