Correct the value of CHASSIS_ON_FILE

Issue: When BMC turns on the host then reboot BMC. The BMC can not turn
off/on or power cycle the host.

Root cause: After commit [1], this repo is using std::format instead
fmt::format. The value of CHASSIS_ON_FILE was not updated in that
commit. It makes the /run/openbmc/chassis@0-on file is not removed when
Chassis' Power state is On, therefore, the BMC can not turn on the host.

Solution: This commit corrects the value of CHASSIS_ON_FILE.

[1] https://github.com/openbmc/phosphor-state-manager/commit/78c066f6078704fd202c8a4b02fcf73091481ef1

Change-Id: Ib741022774aac9a5cb3a4adc87bae8583df97ce2
Signed-off-by: Thang Tran <thuutran@amperecomputing.com>
diff --git a/meson.build b/meson.build
index 55f9b47..d3d04f6 100644
--- a/meson.build
+++ b/meson.build
@@ -81,7 +81,7 @@
     'HOST_RUNNING_FILE', '/run/openbmc/host@{}-on')
 
 conf.set_quoted(
-    'CHASSIS_ON_FILE', '/run/openbmc/chassis@%d-on')
+    'CHASSIS_ON_FILE', '/run/openbmc/chassis@{}-on')
 
 configure_file(output: 'config.h', configuration: conf)