add braces and fix indentation

Objects/stringobject.c

@@ -3125,7 +3125,7 @@ string_expandtabs(PyStringObject *self, PyObject *args)
     q = PyString_AS_STRING(u); /* next output char */
     qe = PyString_AS_STRING(u) + PyString_GET_SIZE(u); /* end of output */
 
-    for (p = PyString_AS_STRING(self); p < e; p++)
+    for (p = PyString_AS_STRING(self); p < e; p++) {
         if (*p == '\t') {
             if (tabsize > 0) {
                 i = tabsize - (j % tabsize);
@@ -3145,6 +3145,7 @@ string_expandtabs(PyStringObject *self, PyObject *args)
             if (*p == '\n' || *p == '\r')
                 j = 0;
         }
+    }
 
     return u;