tests/extmod/vfs_posix_paths.py: Use tuple instead of set.

So it can be used on targets without set enabled (or at least not raise a
SyntaxError when compiling it).

Signed-off-by: Damien George <damien@micropython.org>

tests/extmod/vfs_posix_paths.py

@@ -31,7 +31,7 @@ fs.mkdir("subdir")
 fs.mkdir("subdir/one")
 print('listdir("/"):', sorted(i[0] for i in fs.ilistdir("/")))
 print('listdir("."):', sorted(i[0] for i in fs.ilistdir(".")))
-print('getcwd() in {"", "/"}:', fs.getcwd() in {"", "/"})
+print('getcwd() in ("", "/"):', fs.getcwd() in ("", "/"))
 print('chdir("subdir"):', fs.chdir("subdir"))
 print("getcwd():", fs.getcwd())
 print('mkdir("two"):', fs.mkdir("two"))

tests/extmod/vfs_posix_paths.py.exp

@@ -1,6 +1,6 @@
 listdir("/"): ['subdir']
 listdir("."): ['subdir']
-getcwd() in {"", "/"}: True
+getcwd() in ("", "/"): True
 chdir("subdir"): None
 getcwd(): /subdir
 mkdir("two"): None