test: make zdtm.py python2/python3 compatible

Cc: Adrian Reber <areber@redhat.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>

test/inhfd/fifo.py

@@ -8,8 +8,8 @@ def create_fds():
 		raise Exception("Unable to mount tmpfs")
 	tfifo = os.path.join(tdir, "test_fifo")
 	os.mkfifo(tfifo)
-	fd2 = open(tfifo, "w+")
-	fd1 = open(tfifo, "r")
+	fd2 = open(tfifo, "w+b", buffering=0)
+	fd1 = open(tfifo, "rb")
 	os.system("umount -l %s" % tdir)
 	os.rmdir(tdir)
 

test/inhfd/pipe.py

@@ -2,7 +2,7 @@ import os
 
 def create_fds():
 	(fd1, fd2) = os.pipe()
-	return (os.fdopen(fd2, "w"), os.fdopen(fd1, "r"))
+	return (os.fdopen(fd2, "wb"), os.fdopen(fd1, "rb"))
 
 def filename(pipef):
 	return 'pipe:[%d]' % os.fstat(pipef.fileno()).st_ino

test/inhfd/socket.py

@@ -3,7 +3,7 @@ import os
 
 def create_fds():
 	(sk1, sk2) = socket.socketpair(socket.AF_UNIX, socket.SOCK_STREAM)
-	return (sk1.makefile("w"), sk2.makefile("r"))
+	return (sk1.makefile("wb"), sk2.makefile("rb"))
 
 def __sock_ino(sockf):
 	return os.fstat(sockf.fileno()).st_ino

test/inhfd/tty.py

@@ -6,7 +6,7 @@ def child_prep(fd):
 
 def create_fds():
 	(fd1, fd2) = pty.openpty()
-	return (os.fdopen(fd2, "w"), os.fdopen(fd1, "r"))
+	return (os.fdopen(fd2, "wb"), os.fdopen(fd1, "rb"))
 
 def filename(pipef):
 	st = os.fstat(pipef.fileno())