libc/uClibc: fix building on system with recent glibc

While trying to build a toolchain with ct-ng 1.5.0,
arm-unknown-linux-uclibcgnueabi target,
I get the following error:

[INFO ] Installing C library headers
[EXTRA] Copying sources to build dir
[EXTRA] Applying configuration
[EXTRA] Building headers
[EXTRA] Installing headers
[ERROR] extra/scripts/unifdef.c:209: error: conflicting types for 'getline'
[ERROR] make[2]: *** [extra/scripts/unifdef] Error 1
[ERROR] Build failed in step 'Installing C library headers'

The following patch solves the problem.
(It's a backport of this uClibc commit:
http://git.uclibc.org/uClibc/commit/?id=49e81cada73616864b9b31df0aeb6961c30f5a6e
)

[--SNIP from another mail--]
AFAIK this is a problem since glibc 2.10.
(transplanted from 1ba79f2126df8bd89120899a58f2d0bcc2e9c771)

 reporter_name="Nate CASE"

 reporter_url="http://sourceware.org/ml/crossgcc/2008-10/msg00016.html"

 reporter_comment="This is a sample config file for Freescale e500v2 processors (e.g.,

 MPC8548, MPC8572).  It uses eglibc (for e500/SPE patches) and a recent

 gcc (4.3.1, for e500v2 DPFP support) and will generate appropriate

 dual-precision floating point instructions by default.

 Note: If building a Linux kernel with this toolchain, you will want to

 make sure -mno-spe AND -mspe=no are passed to gcc to prevent SPE

 ABI/instructions from getting into the kernel (which is currently

 unsupported).  At this time, the kernel build system only passes

 -mno-spe by default (this should be fixed soon hopefully)."