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/main_ipmi.cpp b/ipmi/main_ipmi.cpp
index d867dd5..93eee63 100644
--- a/ipmi/main_ipmi.cpp
+++ b/ipmi/main_ipmi.cpp
@@ -25,15 +25,12 @@
 #include <functional>
 #include <memory>
 
-namespace pid_control
-{
-namespace ipmi
+namespace pid_control::ipmi
 {
 
 ZoneControlIpmiHandler handler(std::make_unique<DbusZoneControl>());
 
-}
-} // namespace pid_control
+} // namespace pid_control::ipmi
 
 void setupGlobalOemFanControl() __attribute__((constructor));