build: fix build of renameat2 on Alpine Linux

* gnulib: The only change included in this update
it the added check for the presence of <linux/fs.h>
which is not present on Alpine Linux by default.

diff --git a/gnulib b/gnulib
index 8d116e3f657cb120f79efbbb675fa3cc9d21f53e..58c0514fa38c16ebef9db95e215195570862f872 160000 (submodule)
--- a/gnulib
+++ b/gnulib
@@ -1 +1 @@
-Subproject commit 8d116e3f657cb120f79efbbb675fa3cc9d21f53e
+Subproject commit 58c0514fa38c16ebef9db95e215195570862f872