Revert "Name function arguments in libc headers for Studio."

This reverts commit 079bff4fa52b0c3c76057451cc9cdecf1827fce0.

Broke builds with SANITIZE_HOST=address with an asan failure in versioner.

Change-Id: I22b113fd5405589d1a25e5e137c450aaba1ade5f
diff --git a/libc/include/sys/eventfd.h b/libc/include/sys/eventfd.h
index 3cfb5e7..6b9749a 100644
--- a/libc/include/sys/eventfd.h
+++ b/libc/include/sys/eventfd.h
@@ -37,13 +37,14 @@
 #define EFD_CLOEXEC O_CLOEXEC
 #define EFD_NONBLOCK O_NONBLOCK
 
+/* type of event counter */
 typedef uint64_t eventfd_t;
 
-int eventfd(unsigned int __initial_value, int __flags);
+int eventfd(unsigned int initial_value, int flags);
 
-int eventfd_read(int __fd, eventfd_t* __value);
-int eventfd_write(int __fd, eventfd_t __value);
+int eventfd_read(int fd, eventfd_t* value);
+int eventfd_write(int fd, eventfd_t value);
 
 __END_DECLS
 
-#endif
+#endif /* _SYS_EVENTFD_H */