POSIX now uses libmem/malloc instead of the built-in one.

(cherry picked from commit 48adbffa6514755385af842f1fe8ca5068229eea)

conts/posix/mm0/fs/path.c

@@ -7,7 +7,7 @@
 #include <l4/lib/list.h>
 #include <l4/api/errno.h>
 #include <lib/pathstr.h>
-#include <lib/malloc.h>
+#include <malloc/malloc.h>
 #include <path.h>
 #include <stdio.h>
 #include <fs.h>