rewrite comments into one, unified style

code/user/personalities/posix/posix_path.h

@@ -1,5 +1,7 @@
+// POSIX compatibility support for posix path.
+
 #pragma once
-// posix_path.h - POSIX <-> native path translation
+// posix_path.h - POSIX <-> native path translation.
 
 // SYNTHETIC sentinel returned from PosixTranslatePath for /dev/null and
 // /dev/zero; the caller must handle these before passing to any syscall.