hv_utils: Fix spelling mistake "Hearbeat" -> "Heartbeat"

There is a spelling mistake in an error message. Fix it.
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Link: https://lore.kernel.org/r/20210127233136.623465-1-colin.king@canonical.comSigned-off-by: Wei Liu <wei.liu@kernel.org>

drivers/hv/hv_util.c

@@ -507,7 +507,7 @@ static void heartbeat_onchannelcallback(void *context)
 
 		/* Ensure recvlen is big enough to read header data */
 		if (recvlen < ICMSG_HDR) {
-			pr_err_ratelimited("Hearbeat request received. Packet length too small: %d\n",
+			pr_err_ratelimited("Heartbeat request received. Packet length too small: %d\n",
 					   recvlen);
 			break;
 		}