Name function arguments in libc headers for Studio.

Second batch of headers...

Bug: http://b/64613623
Test: builds
Change-Id: I8eef043dbf32afee8ff814e9d005f46aee8fa21f
diff --git a/libc/include/sys/personality.h b/libc/include/sys/personality.h
index 6f3a3c9..51b5cd7 100644
--- a/libc/include/sys/personality.h
+++ b/libc/include/sys/personality.h
@@ -34,8 +34,8 @@
 
 __BEGIN_DECLS
 
-int personality(unsigned int persona) __INTRODUCED_IN(15);
+int personality(unsigned int __persona) __INTRODUCED_IN(15);
 
 __END_DECLS
 
-#endif /* _SYS_PERSONALITY_H_ */
+#endif