fix(docbuild): Fix @file commands and guard macros. (#6689)

src/stdlib/lv_sprintf.h

@@ -1,10 +1,10 @@
 /**
- * lv_snprintf.h
+ * @file lv_sprintf.h
  *
  */
 
-#ifndef LV_SPRINTF_H_
-#define LV_SPRINTF_H_
+#ifndef LV_SPRINTF_H
+#define LV_SPRINTF_H
 
 #if defined(__has_include)
     #if __has_include(LV_INTTYPES_INCLUDE)
@@ -42,4 +42,4 @@ int lv_vsnprintf(char * buffer, size_t count, const char * format, va_list va);
 } /*extern "C"*/
 #endif
 
-#endif  /* LV_SPRINTF_H_*/
+#endif  /* LV_SPRINTF_H */