Update the registered IPMI method name

Update registered IPMI method names to use `Lower Camel Case`.

Change-Id: I5539771c4ba8567f6cdb22aa3c8df58db5e883f2
Signed-off-by: George Liu <liuxiwei@ieisystem.com>
diff --git a/groupext.cpp b/groupext.cpp
index 66d02f8..222ce9a 100644
--- a/groupext.cpp
+++ b/groupext.cpp
@@ -3,7 +3,7 @@
 #include <cstdio>
 
 #define GRPEXT_GET_GROUP_CMD 0
-void register_netfn_groupext_functions() __attribute__((constructor));
+void registerNetFnGroupExtFunctions() __attribute__((constructor));
 
 ipmi_ret_t ipmi_groupext(ipmi_netfn_t, ipmi_cmd_t, ipmi_request_t,
                          ipmi_response_t response, ipmi_data_len_t data_len,
@@ -21,7 +21,7 @@
     return rc;
 }
 
-void register_netfn_groupext_functions()
+void registerNetFnGroupExtFunctions()
 {
     // <Group Extension Command>
     ipmi_register_callback(NETFUN_GRPEXT, GRPEXT_GET_GROUP_CMD, NULL,