libtraceevent: update to 1.7.3
ChangeLog:
dd14818 libtraceevent: version 1.7.3
0b9a34e libtraceevent: Handle printf '%+d" case
eba4a41 libtraceevent: Add initial support for meson
1d8ddb9 libtraceevent: Handle %c
Signed-off-by: Nick Hainke <[email protected]>