sockaddr_str.h Fix OSMO_SOCKADDR_STR_FMT_ARGS_NOT_NULL syntax error

It's fine changing the define because due to the previous error it means
basically that it was never used so far, because using it triggers a
compilation error.

The error was introduced because I ended up not using this in the past
after submitting this code, and now that I want to use it it went
noticed that it fails.

Change-Id: Iee361d740845257fa62c9093e30e8079fa933827
(cherry picked from commit d9a5c8d32f10af0479c87b957fd7e23cecb8fcce)
---
M include/osmocom/core/sockaddr_str.h
1 file changed, 19 insertions(+), 1 deletion(-)

diff --git a/include/osmocom/core/sockaddr_str.h b/include/osmocom/core/sockaddr_str.h
index 2d3e7e9..c646f49 100644
--- a/include/osmocom/core/sockaddr_str.h
+++ b/include/osmocom/core/sockaddr_str.h
@@ -63,7 +63,7 @@
 	((R)->af == AF_INET6) ? "[" : "", \
 	(R)->ip, \
 	((R)->af == AF_INET6) ? "]" : "", \
-	(R)->port : 0
+	(R)->port
 #define OSMO_SOCKADDR_STR_FMT_ARGS(R) \
 	((R) && (R)->af == AF_INET6) ? "[" : "", \
 	(R) ? (R)->ip : "NULL", \

