[babl] bug #778071 improve portability to hp-ux native compiler

[Øyvind Kolås <ok src gnome org>]

commit 732847d1f81a92a896922f51f4945c710f1aea9c
Author: Øyvind Kolås <pippin gimp org>
Date:   Thu Feb 9 12:44:07 2017 +0100

    bug #778071 improve portability to hp-ux native compiler

 babl/base/pow-24.h |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/babl/base/pow-24.h b/babl/base/pow-24.h
index 5271b40..0defef6 100644
--- a/babl/base/pow-24.h
+++ b/babl/base/pow-24.h
@@ -88,7 +88,7 @@ static inline float babl_frexpf(float x, int *e)
 
         if (!ee) {
                 if (x) {
-                        x = babl_frexpf(x*0x1p64, e);
+                        x = babl_frexpf(x*18446744073709551616.0, e);
                         *e -= 64;
                 } else *e = 0;
                 return x;