Correct _PyLong_Frexp() description in comments (GH-132716)

This amends d08c788, now this function always successful.

Author: skirpichev

Objects/longobject.c

@@ -3438,9 +3438,7 @@ x_divrem(PyLongObject *v1, PyLongObject *w1, PyLongObject **prem)
 /* For a nonzero PyLong a, express a in the form x * 2**e, with 0.5 <=
    abs(x) < 1.0 and e >= 0; return x and put e in *e.  Here x is
    rounded to DBL_MANT_DIG significant bits using round-half-to-even.
-   If a == 0, return 0.0 and set *e = 0.  If the resulting exponent
-   e is larger than PY_SSIZE_T_MAX, raise OverflowError and return
-   -1.0. */
+   If a == 0, return 0.0 and set *e = 0.  */
 
 /* attempt to define 2.0**DBL_MANT_DIG as a compile-time constant */
 #if DBL_MANT_DIG == 53