Remove from documentation struct names not used.

Remove from documentation struct names not used.

There are some structs defined as:
typedef struct _Foo {
...
} Foo;

With this patch, only Foo shows up in the documentation instead
of _Foo.

git-svn-id: https://src.develer.com/svnoss/bertos/trunk@4670 38d2e660-2303-0410-9eaa-f027e97ec537