Fix invalid XML docs (#2005)

Xamarin.Flex/Flex.cs

@@ -387,10 +387,9 @@ namespace Xamarin.Flex
 			Height = height;
 		}
 
-		/// <param name="child">The child item to be added.</param>
 		/// <summary>Adds a given child item to the current item.</summary>
 		/// <exception cref = "ArgumentException" > Thrown if the child has already been added to another item.</exception>
-		/// <param name="child">Child.</param>
+		/// <param name="child">The child item to be added.</param>
 		public void Add(Item child)
 		{
 			ValidateChild(child);

Xamarin.Forms.Core/OrderedDictionary.cs

@@ -79,9 +79,7 @@ namespace Cadenza.Collections
 		}
 
 		/// <summary>
-		///     Gets the equality comparer being used for
-		///     <typeparam name="TKey" />
-		///     .
+		///     Gets the equality comparer being used for <typeparamref name="TKey"/>.
 		/// </summary>
 		public IEqualityComparer<TKey> Comparer
 		{