tst_tmpdir: Print used temporary dir and its filesystem

It helps debugging to know used filesystem (and in case of
.all_filesystems the underlying filesystem).

Link: https://lore.kernel.org/ltp/20240724071123.923397-1-pvorel@suse.cz/
Reviewed-by: Li Wang <liwang@redhat.com>
Signed-off-by: Petr Vorel <pvorel@suse.cz>

lib/tst_tmpdir.c

@@ -312,6 +312,9 @@ void tst_tmpdir(void)
 
 		tst_exit();
 	}
+
+	tst_resm(TINFO, "Using %s as tmpdir (%s filesystem)", TESTDIR,
+			 tst_fs_type_name(tst_fs_type(NULL, TESTDIR)));
 }
 
 void tst_rmdir(void)