Fix syntax error

Author: jyscao

pandas/io/sas/sas_xport.py

@@ -367,7 +367,7 @@ def _read_header(self):
             fl = field["field_length"]
             if field["ntype"] == "numeric" and ((fl < 2) or (fl > 8)):
                 self.close()
-                msg = "f{Floating field width {fl} is not between 2 and 8.}"
+                msg = f"{Floating field width {fl} is not between 2 and 8.}"
                 raise TypeError(msg)
 
             for k, v in field.items():