Move mkpathat to lib, remove redundant function used by patch.
diff --git a/lib/lib.h b/lib/lib.h
index 6355b3e..56927b8 100644
--- a/lib/lib.h
+++ b/lib/lib.h
@@ -110,7 +110,6 @@
 char *xrealpath(char *path);
 void xchdir(char *path);
 void xchroot(char *path);
-void xmkpath(char *path, int mode);
 struct passwd *xgetpwuid(uid_t uid);
 struct group *xgetgrgid(gid_t gid);
 struct passwd *xgetpwnam(char *name);
@@ -128,6 +127,7 @@
 ssize_t readall(int fd, void *buf, size_t len);
 ssize_t writeall(int fd, void *buf, size_t len);
 off_t lskip(int fd, off_t offset);
+int mkpathat(int atfd, char *dir, mode_t lastmode, int flags);
 struct string_list **splitpath(char *path, struct string_list **list);
 char *readfile(char *name, char *buf, off_t len);
 void msleep(long miliseconds);