Remove provider language from docs (#3072)

diff --git a/docs/hazmat/primitives/padding.rst b/docs/hazmat/primitives/padding.rst
index 0b76327..b346b59 100644
--- a/docs/hazmat/primitives/padding.rst
+++ b/docs/hazmat/primitives/padding.rst
@@ -45,13 +45,13 @@
 
         :returns: A padding
             :class:`~cryptography.hazmat.primitives.padding.PaddingContext`
-            provider.
+            instance.
 
     .. method:: unpadder()
 
         :returns: An unpadding
             :class:`~cryptography.hazmat.primitives.padding.PaddingContext`
-            provider.
+            instance.
 
 
 .. class:: ANSIX923(block_size)
@@ -88,13 +88,13 @@
 
         :returns: A padding
             :class:`~cryptography.hazmat.primitives.padding.PaddingContext`
-            provider
+            instance.
 
     .. method:: unpadder()
 
         :returns: An unpadding
             :class:`~cryptography.hazmat.primitives.padding.PaddingContext`
-            provider.
+            instance.
 
 
 .. class:: PaddingContext