libc/{glibc,eglibc}: Don't download glibc-ports when not available

Don't download glibc-ports when glibc or eglibc version greater than 2.16,
because the "ports" source is mainline in the glibc or eglibc since version 2.17.

Signed-off-by: "Daniel Zimmermann" <netzimme@gmail.com>
Message-Id: <9c045ca3cf1b9dc89da3.1384602843@haus-VirtualBox>
Patchwork-Id: 291766
[yann.morin.1998@free.fr: slightly tweak subject, change variable name]
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>

--- trunk/src/acos.c	2009/12/08 16:49:43	733

+++ trunk/src/acos.c	2009/12/09 20:51:38	734

@@ -188,10 +188,7 @@

   else

     rnd_im = rnd_im == GMP_RNDU ? GMP_RNDD

       : rnd_im == GMP_RNDD ? GMP_RNDU

-#if MPFR_VERSION_MAJOR >= 3

-      : rnd_im == GMP_RNDA ? GMP_RNDZ

-#endif

-      : rnd_im;

+      : rnd_im; /* both RNDZ and RNDA map to themselves for -asin(z) */

   rnd1 = RNDC(GMP_RNDN, rnd_im);

   mpfr_init2 (pi_over_2, p);

   for (;;)