Use initalization instead of explicit zeroing

Before, we would initialize many fields twice: first
by filling the structure with zeros, and then a second
time with the real values. We can let the compiler do
the job for us, avoiding one copy.

A downside of this patch is that text gets slightly
bigger. This is because all zero() calls are effectively
inlined:

$ size build/.libs/systemd
         text    data     bss     dec     hex filename
before 897737  107300    2560 1007597   f5fed build/.libs/systemd
after  897873  107300    2560 1007733   f6075 build/.libs/systemd

… actually less than 1‰.

A few asserts that the parameter is not null had to be removed. I
don't think this changes much, because first, it is quite unlikely
for the assert to fail, and second, an immediate SEGV is almost as
good as an assert.

1 files changed, 3 insertions, 7 deletions

diff --git a/src/login/loginctl.c b/src/login/loginctl.c
index 6c229c64e3..36c65bc8d0 100644
--- a/src/login/loginctl.c
+++ b/src/login/loginctl.c
@@ -834,17 +834,13 @@ static int show_one(const char *verb, DBusConnection *bus, const char *path, boo
         const char *interface = "";
         int r;
         DBusMessageIter iter, sub, sub2, sub3;
-        SessionStatusInfo session_info;
-        UserStatusInfo user_info;
-        SeatStatusInfo seat_info;
+        SessionStatusInfo session_info = {};
+        UserStatusInfo user_info = {};
+        SeatStatusInfo seat_info = {};
 
         assert(path);
         assert(new_line);
 
-        zero(session_info);
-        zero(user_info);
-        zero(seat_info);
-
         r = bus_method_call_with_reply(
                         bus,
                         "org.freedesktop.login1",