Fix typo in SHA512 documentation (#8429)

Author: vcsjones

xml/System.Security.Cryptography/SHA512.xml

@@ -441,7 +441,7 @@
         <summary>Computes the hash of data using the SHA512 algorithm.</summary>
         <returns>The total number of bytes written to <paramref name="destination" />.</returns>
         <remarks>To be added.</remarks>
-        <exception cref="T:System.ArgumentException">The buffer in <paramref name="destination" /> is too small to hold the calculated hash size. The SHA1 algorithm always produces a 512-bit hash, or 64 bytes.</exception>
+        <exception cref="T:System.ArgumentException">The buffer in <paramref name="destination" /> is too small to hold the calculated hash size. The SHA512 algorithm always produces a 512-bit hash, or 64 bytes.</exception>
       </Docs>
     </Member>
     <Member MemberName="HashDataAsync">