mainapp: Fix postcode path

This was changed from /raw to /raw0

Change-Id: Idf99ffa36aca41ff5da5bab357ab6446cff737ee
Signed-off-by: William A. Kennington III <wak@google.com>
diff --git a/src/mainapp.cpp b/src/mainapp.cpp
index 06b22ec..34c7ed9 100644
--- a/src/mainapp.cpp
+++ b/src/mainapp.cpp
@@ -230,7 +230,7 @@
             watchPostcodeMatch.emplace(
                 bus,
                 sdbusplus::bus::match::rules::propertiesChanged(
-                    "/xyz/openbmc_project/state/boot/raw",
+                    "/xyz/openbmc_project/state/boot/raw0",
                     "xyz.openbmc_project.State.Boot.Raw"),
                 std::bind(&Watchdog::resetTimeRemaining, std::ref(watchdog),
                           false));