tests/extmod/framebuf1: Fix test for framebuf invalid constructor.

tests/extmod/framebuf1.py

@@ -89,11 +89,11 @@ print(buf)
 fbuf.text(str(chr(31)), 0, 0)
 print(buf)
 
-# test invalid constructor
+# test invalid constructor, and stride argument
 try:
-    fbuf = framebuf.FrameBuffer(buf, w, h, 3, framebuf.MVLSB)
+    fbuf = framebuf.FrameBuffer(buf, w, h, -1, w)
 except ValueError:
-	print("ValueError")
+    print("ValueError")
 
 # test legacy constructor
 fbuf = framebuf.FrameBuffer1(buf, w, h)