Fix CA2022: Avoid inexact read with Stream.Read

Author: claudiamurialdo

dotnet/src/dotnetframework/GxClasses/Domain/GxFtp.cs

@@ -847,9 +847,13 @@ private bool IsCompleteResponse(Stream responseStream)
 			{
 				int StatusCode=-1;									
 				Byte[] ByteArray = new Byte[responselength];			
-				String statuscodestr;							
-				responseStream.Read(ByteArray,0,responselength);		
-				statuscodestr=Encoding.ASCII.GetString(ByteArray,0,responselength);			
+				String statuscodestr;
+#if NETCORE
+				responseStream.ReadExactly(ByteArray,0,responselength);
+#else
+				responseStream.Read(ByteArray, 0, responselength);
+#endif
+				statuscodestr = Encoding.ASCII.GetString(ByteArray,0,responselength);			
 				if (responselength==5 && ByteArray[responselength-1] == '\n')	
 				{