Use api.hpp instead of api.h

Since the api.h file has been gradually deprecated, this submission
will use api.hpp instead of api.h

Change-Id: Ic9c8ebe0ba96b0a11b9415cd52acdf58fe9d828e
Signed-off-by: George Liu <liuxiwei@ieisystem.com>
Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
diff --git a/ipmi/dbus_mode.hpp b/ipmi/dbus_mode.hpp
index c073162..7a23e52 100644
--- a/ipmi/dbus_mode.hpp
+++ b/ipmi/dbus_mode.hpp
@@ -5,9 +5,7 @@
 #include <cstdint>
 #include <string>
 
-namespace pid_control
-{
-namespace ipmi
+namespace pid_control::ipmi
 {
 
 class DbusZoneControl : public ZoneControlInterface
@@ -36,5 +34,4 @@
                                const std::string& property) override;
 };
 
-} // namespace ipmi
-} // namespace pid_control
+} // namespace pid_control::ipmi