eglibc: fix builds on fedora 17 alpha

eglibc: fix builds on fedora 17 alpha

Generally distros keep perl at /sur/bin/perl
Fedora 17 alpha also has /bin/perl

this causes eglibc build on such distros to put perl interpreter path in
the perl scripts as /bin/perl

But we set perl location for target as /usr/bin/perl

This mismatch of perl path causes failure of rootfs image creation
like this:

| error: Failed dependencies:
|       /bin/perl is needed by eglibc-utils-2.13-r23+svnr15508.i586
NOTE: package core-image-sato-1.0-r0: task do_rootfs: Failed
ERROR: Task 8
(/home/nitin/prj/poky.git/meta/recipes-sato/images/core-image-sato.bb,
do_rootfs) failed with exit code '1'

This Fixes bug : [YOCTO #2286]

RP: Updated to better account for -nativesdk
(From OE-Core rev: 381bf0d364da5970682502f8f124264907587b87)

Signed-off-by: Nitin A Kamble <nitin.a.kamble@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>