fix typo

Author: pedrobsaila

xml/System.IO.Pipelines/PipeWriter.xml

@@ -75,7 +75,7 @@
         <param name="bytes">The number of bytes written to the <see cref="T:System.Span`1" /> or <see cref="T:System.Memory`1" />.</param>
         <summary>Notifies the <see cref="T:System.IO.Pipelines.PipeWriter" /> that <paramref name="bytes" /> bytes were written to the output <see cref="T:System.Span`1" /> or <see cref="T:System.Memory`1" />. You must call <see cref="M:System.IO.Pipelines.PipeWriter.GetSpan(System.Int32)" /> or <see cref="M:System.IO.Pipelines.PipeWriter.GetMemory(System.Int32)" /> again and use the returned buffer to continue writing more data after calling <see cref="M:System.IO.Pipelines.PipeWriter.Advance(System.Int32)" />; you cannot write to a previously acquired buffer.</summary>
         <remarks>To be added.</remarks>
-        <exception cref="T:System.OverflowException">The buffer size overflown its `long.MaxValue` max size.</exception>
+        <exception cref="T:System.OverflowException">The unflushed buffer overflowed its `long.MaxValue` max size.</exception>
       </Docs>
     </Member>
     <Member MemberName="AsStream">