Update SafeBuffer.xml (dotnet#9120)

Fixes dotnet#9097

Author: AaronRobinsonMSFT

xml/System.Runtime.InteropServices/SafeBuffer.xml

@@ -199,7 +199,7 @@
 ## Remarks  
  When <xref:System.Runtime.InteropServices.SafeBuffer.AcquirePointer%2A> returns, you should perform bounds checking by verifying that the `pointer` parameter is `null`. If it is not `null`, you must call the <xref:System.Runtime.InteropServices.SafeBuffer.ReleasePointer%2A?displayProperty=nameWithType> method in a constrained execution region (CER).  
   
- <xref:System.Runtime.InteropServices.SafeBuffer.AcquirePointer%2A> calls the <xref:System.Runtime.InteropServices.SafeHandle.DangerousAddRef%2A?displayProperty=nameWithType> method and exposes the pointer. Unlike the <xref:System.Runtime.InteropServices.SafeBuffer.Read%2A> method, it does not change the current position of the pointer.  
+ <xref:System.Runtime.InteropServices.SafeBuffer.AcquirePointer%2A> calls the <xref:System.Runtime.InteropServices.SafeHandle.DangerousAddRef%2A?displayProperty=nameWithType> method and exposes the pointer.
   
  The following example demonstrates how to use the <xref:System.Runtime.InteropServices.SafeBuffer.AcquirePointer%2A> method: