Install parallel issue

[RomainNaour]

Hi,

With a fast build server, make install fail when a symlink to usr/share/bash-completion/completions/7z is created before creating usr/share/bash-completion/completions directory.
It seems that a installdirs dependency is missing on symlinks Makefile target.

make[3]: Nothing to be done for install-exec-am'. for file in 7za ; do \ rm -f /home/peko/autobuild/instance-0/output/host/arm-buildroot-linux-gnueabi/sysroot/usr/share/bash-completion/completions/$file && \ ln -s 7z /home/peko/autobuild/instance-0/output/host/arm-buildroot-linux-gnueabi/sysroot/usr/share/bash-completion/completions/$file ; \ done /bin/mkdir -p '/home/peko/autobuild/instance-0/output/host/arm-buildroot-linux-gnueabi/sysroot/usr/share/bash-completion/completions' ln: failed to create symbolic link /home/peko/autobuild/instance-0/output/host/arm-buildroot-linux-gnueabi/sysroot/usr/share/bash-completion/completions/7za': No such file or directory

See complete build log:
http://autobuild.buildroot.net/results/7eea0f512695605714cf2d8c971778d4784b4c75/build-end.log