Update basic-filebuf-class.md

Colin Robertson · web-flow · commit 9fb7c7448d00 · 2020-03-03T14:28:53.000-08:00
Fix gremlin quote, consolidate return value sentence.
diff --git a/docs/standard-library/basic-filebuf-class.md b/docs/standard-library/basic-filebuf-class.md
@@ -300,7 +300,7 @@ bool is_open() const;
 
 ### Return Value
 
-**true** if the file pointer isn’t null.
+**true** if the file pointer isn't null.
 
 ### Example
 
@@ -371,9 +371,7 @@ The default file opening protection, equivalent to the *shflag* parameter in [_f
 
 ### Return Value
 
-If the buffer is already open, the function returns a null pointer.
-
-If the file pointer is a null pointer, the function returns a null pointer. Otherwise, it returns **this**.
+If the buffer is already open, or if the file pointer is a null pointer, the function returns a null pointer. Otherwise, it returns **this**.
 
 ### Remarks
 
