rename variables for consistency

Signed-off-by: Ianto Lin Xi <iantolinxi@gmail.com>

tests/integration/container_test.py

@@ -982,9 +982,9 @@ def test_run_container_stdin_tty(self):
 
         self.client.start(ident)
 
-        stdout = self.client.attach(ident, stdin=line, logs=True, stream=True)
+        data = self.client.attach(ident, stdin=line, logs=True, stream=True)
 
-        output = "".join([next(stdout).decode("utf-8") for _ in
+        output = "".join([next(data).decode("utf-8") for _ in
                           range(len(line))])
 
         self.assertEqual(output, line)
@@ -999,8 +999,8 @@ def test_run_container_stdin_string(self):
 
         self.client.start(ident)
 
-        stdio = self.client.attach(ident, stdin=line, logs=True, stream=True)
-        output = next(stdio).decode("utf-8")
+        data = self.client.attach(ident, stdin=line, logs=True, stream=True)
+        output = next(data).decode("utf-8")
         self.assertEqual(output, line)
 
     def test_run_container_stdin_bytes(self):
@@ -1013,8 +1013,8 @@ def test_run_container_stdin_bytes(self):
 
         self.client.start(ident)
 
-        stdio = self.client.attach(ident, stdin=line, logs=True, stream=True)
-        output = next(stdio)
+        data = self.client.attach(ident, stdin=line, logs=True, stream=True)
+        output = next(data)
         self.assertEqual(output, line)