Doxygen: fix missing documentation for structs

instruct Doxygen to discard GCC attributes when parsing header files

Doxyfile

@@ -2417,15 +2417,15 @@ ENABLE_PREPROCESSING   = YES
 # The default value is: NO.
 # This tag requires that the tag ENABLE_PREPROCESSING is set to YES.
 
-MACRO_EXPANSION        = NO
+MACRO_EXPANSION        = YES
 
 # If the EXPAND_ONLY_PREDEF and MACRO_EXPANSION tags are both set to YES then
 # the macro expansion is limited to the macros specified with the PREDEFINED and
 # EXPAND_AS_DEFINED tags.
 # The default value is: NO.
 # This tag requires that the tag ENABLE_PREPROCESSING is set to YES.
 
-EXPAND_ONLY_PREDEF     = NO
+EXPAND_ONLY_PREDEF     = YES
 
 # If the SEARCH_INCLUDES tag is set to YES, the include files in the
 # INCLUDE_PATH will be searched if a #include is found.
@@ -2458,7 +2458,7 @@ INCLUDE_FILE_PATTERNS  =
 # recursively expanded use the := operator instead of the = operator.
 # This tag requires that the tag ENABLE_PREPROCESSING is set to YES.
 
-PREDEFINED             =
+PREDEFINED             = __attribute__((x))=
 
 # If the MACRO_EXPANSION and EXPAND_ONLY_PREDEF tags are set to YES then this
 # tag can be used to specify a list of macro names that should be expanded. The

xzre.h

@@ -511,12 +511,9 @@ assert_offset(elf_lib_info_t, elf_info, 8);
 /**
  * @brief this structure is used to hold most of the backdoor information.
  * it's used as a local variable in function @ref backdoor_setup
- * 
- * @return typedef struct 
  */
-typedef struct __attribute__((packed)) backdoor_data {
+typedef struct __attribute__((packed)) {
 	PADDING(0x30);
-	// elf_lib_info_t
 	PADDING(sizeof(elf_lib_info_t));
 
 	/**