target is used in glibc fake

if make_os is called without e.g. export target=$PWD/rootfs yum install glibc-common fails:

Install  12 Packages (+170 Dependent packages)

Total size: 123 M
Total download size: 3.6 M
Installed size: 445 M
/usr/sbin/realldconfig: Can't link /lib64/p11-kit-trust.so to libnssckbi.so
/usr/sbin/iconvconfig: cannot open `/usr/lib/gconv/gconv-modules': No such file or directory
/usr/sbin/iconvconfig: no output file produced because warnings were issued
warning: %post(glibc-2.17-222.el7.x86_64) scriptlet failed, exit status 1
Non-fatal POSTIN scriptlet failure in rpm package glibc-2.17-222.el7.x86_64
/usr/sbin/build-locale-archive.rootfs: cannot open directory "/usr/lib/locale/": No such file or directory
/usr/sbin/realldconfig: Can't link /lib64/p11-kit-trust.so to libnssckbi.so
/usr/sbin/realldconfig: Can't link /lib64/p11-kit-trust.so to libnssckbi.so
/usr/sbin/realldconfig: Can't link /lib64/p11-kit-trust.so to libnssckbi.so
/usr/sbin/realldconfig: Can't link /lib64/p11-kit-trust.so to libnssckbi.so
/usr/sbin/realldconfig: Can't link /lib64/p11-kit-trust.so to libnssckbi.so
/usr/sbin/realldconfig: Can't link /lib64/p11-kit-trust.so to libnssckbi.so
/usr/sbin/realldconfig: Can't link /lib64/p11-kit-trust.so to libnssckbi.so
/usr/sbin/realldconfig: Can't link /lib64/p11-kit-trust.so to libnssckbi.so
/usr/sbin/realldconfig: Can't link /lib64/p11-kit-trust.so to libnssckbi.so
/usr/sbin/realldconfig: Can't link /lib64/p11-kit-trust.so to libnssckbi.so
/usr/sbin/realldconfig: Can't link /lib64/p11-kit-trust.so to libnssckbi.so
/usr/sbin/realldconfig: Can't link /lib64/p11-kit-trust.so to libnssckbi.so
/usr/sbin/realldconfig: Can't link /lib64/p11-kit-trust.so to libnssckbi.so
/usr/sbin/realldconfig: Can't link /lib64/p11-kit-trust.so to libnssckbi.so
/usr/sbin/realldconfig: Can't link /lib64/p11-kit-trust.so to libnssckbi.so
/usr/sbin/realldconfig: Can't link /lib64/p11-kit-trust.so to libnssckbi.so
/usr/sbin/realldconfig: Can't link /lib64/p11-kit-trust.so to libnssckbi.so
/usr/sbin/realldconfig: Can't link /lib64/p11-kit-trust.so to libnssckbi.so
/usr/sbin/realldconfig: Can't link /lib64/p11-kit-trust.so to libnssckbi.so
ln: cannot remove '//etc/pki/ca-trust/source/ca-bundle.legacy.crt': Permission denied
...

Solution:

• remove $target for wrap scripts and use $FAKECHROOT_BASE
• if target and/or BASE not given, export them in make_os.sh