Fix "Float-cast-overflow in powf_"

exp2f_ results before this change:
128.000000 -> 340279770772509196049560342183603601408.000000
128.000015 -> nan
129.000000 -> nan
129.000015 -> inf

Even if overflow would not happen, getting consistent result is much better.

Change-Id: I3eb72824a9bc07eee82c93fa47ffe3f09605d9f2
Reviewed-on: https://skia-review.googlesource.com/c/skcms/+/726416
Reviewed-by: Brian Osman <brianosman@google.com>
1 file changed