stats_tcp: use a default batch size of 5 instead of 1

The configuration defaults for the socket statistics are currently set
to a batch size of 1. This means that only one socket per timer
expiration is scanned. This rate is probably a bit low. To speed things
up a bit we should set the default to 5. Scanning 5 sockets at a time is
still in the affordable range.

Change-Id: I87abc74c00377191f7940c5b8f19d932618fc019
Related: SYS#5701
diff --git a/include/osmocom/core/stats_tcp.h b/include/osmocom/core/stats_tcp.h
index 6b9657a..9bc7111 100644
--- a/include/osmocom/core/stats_tcp.h
+++ b/include/osmocom/core/stats_tcp.h
@@ -1,7 +1,7 @@
 #pragma once
 
 #define TCP_STATS_DEFAULT_INTERVAL 0	/* secs */
-#define TCP_STATS_DEFAULT_BATCH_SIZE 1	/* sockets per interval */
+#define TCP_STATS_DEFAULT_BATCH_SIZE 5	/* sockets per interval */
 
 struct osmo_tcp_stats_config {
 	/* poll interval in seconds, use osmo_stats_tcp_set_interval() to manipulate this value */