Merge pull request pytest-dev#1225 from pytest-dev/skipping-docs-inconsistency

Fix inconsistency in skipif example

Author: RonnyPfannschmidt

doc/en/skipping.rst

@@ -83,8 +83,8 @@ As with all function :ref:`marking <mark>` you can skip test functions at the
 `whole class- or module level`_.  If your code targets python2.6 or above you
 use the skipif decorator (and any other marker) on classes::
 
-    @pytest.mark.skipif(sys.platform != 'win32',
-                        reason="requires windows")
+    @pytest.mark.skipif(sys.platform == 'win32',
+                        reason="does not run on windows")
     class TestPosixCalls:
 
         def test_function(self):
@@ -97,8 +97,8 @@ If your code targets python2.5 where class-decorators are not available,
 you can set the ``pytestmark`` attribute of a class::
 
     class TestPosixCalls:
-        pytestmark = pytest.mark.skipif(sys.platform != 'win32',
-                                        reason="requires Windows")
+        pytestmark = pytest.mark.skipif(sys.platform == 'win32',
+                                        reason="does not run on windows")
 
         def test_function(self):
             "will not be setup or run under 'win32' platform"