Only match on ...State.Host not the namespace

Matching on the ...State.Host namespace includes matching on
sub-interfaces such as ...State.Host.Foo.  We don't need that
here, so just match on the exact interface.

Tested:
Confirmed that PropertiesChanged events on sub-interfaces no
longer match.

Change-Id: I9ea0d145bb16551adc59ba105726ee1535f8c4bf
Signed-off-by: Jason M. Bills <jason.m.bills@intel.com>
diff --git a/src/host_error_monitor.cpp b/src/host_error_monitor.cpp
index f1cab3d..1c6a2e7 100644
--- a/src/host_error_monitor.cpp
+++ b/src/host_error_monitor.cpp
@@ -263,8 +263,7 @@
     return std::make_shared<sdbusplus::bus::match::match>(
         *conn,
         "type='signal',interface='org.freedesktop.DBus.Properties',"
-        "member='PropertiesChanged',arg0namespace='xyz.openbmc_project.State."
-        "Host'",
+        "member='PropertiesChanged',arg0='xyz.openbmc_project.State.Host'",
         [](sdbusplus::message::message& msg) {
             std::string interfaceName;
             boost::container::flat_map<std::string, std::variant<std::string>>