hv: rename prep_negotiate_resp() to vmbus_prep_negotiate_resp()

It's a global symbol, so properly prefix it and use the proper EXPORT
value as well.

Cc: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/hv/hv_util.c b/drivers/hv/hv_util.c
index e0e3a6d..55d58f2 100644
--- a/drivers/hv/hv_util.c
+++ b/drivers/hv/hv_util.c
@@ -73,7 +73,7 @@
 			sizeof(struct vmbuspipe_hdr)];
 
 		if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
-			prep_negotiate_resp(icmsghdrp, negop, shut_txf_buf);
+			vmbus_prep_negotiate_resp(icmsghdrp, negop, shut_txf_buf);
 		} else {
 			shutdown_msg =
 				(struct shutdown_msg_data *)&shut_txf_buf[
@@ -198,7 +198,7 @@
 				sizeof(struct vmbuspipe_hdr)];
 
 		if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
-			prep_negotiate_resp(icmsghdrp, NULL, time_txf_buf);
+			vmbus_prep_negotiate_resp(icmsghdrp, NULL, time_txf_buf);
 		} else {
 			timedatap = (struct ictimesync_data *)&time_txf_buf[
 				sizeof(struct vmbuspipe_hdr) +
@@ -237,7 +237,7 @@
 				sizeof(struct vmbuspipe_hdr)];
 
 		if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
-			prep_negotiate_resp(icmsghdrp, NULL, hbeat_txf_buf);
+			vmbus_prep_negotiate_resp(icmsghdrp, NULL, hbeat_txf_buf);
 		} else {
 			heartbeat_msg =
 				(struct heartbeat_msg_data *)&hbeat_txf_buf[