Simplifies _print_hex method

Simplifies the `_print_hex` method.

Note that there are ~4 different ways of implementing it:
```
In [1]: def a(x):
   ...:     return hex(x).rstrip('L')
   ...: def b(x):
   ...:     s = hex(x)
   ...:     return s[0:-1] if s.endswith("L") else s
   ...: def c(x):
   ...:     return '0x%x' % x
   ...: def d(x):
   ...:     return '0x{:x}'.format(x)
```

pywraps/py_idaapi.py

@@ -694,8 +694,7 @@ class IDAPython_displayhook:
             storage.append(str(item))
 
     def _print_hex(self, x):
-        s = hex(x)
-        return s[0:-1] if s.endswith("L") else s
+        return hex(x).rstrip('L')
 
     def displayhook(self, item):
         if item is None or type(item) is bool: