gcc-cross: aviod creating invalid symlinks

gcc-cross: aviod creating invalid symlinks

There are several invalid symlinks in gcc-cross-initial,
gcc-cross-intermediate and gcc-cross, these cause the error:(56 errors)

tmp/work/i586-poky-linux/gcc-cross-initial-4.6.3+svnr184847-r23/temp/log.do_populate_sysroot:
log.do_populate_sysroot:grep: /path/to/invalid/symlink: No such file or directory

Avoid creating invalid symlinks would fix this problem.

Use the:
[ ! -e file ] || do_something
But not use:
[ -e file ] && do_something
is because that if the "file" doesn't exist, then the whole statement
would return false, and bitbake treats this an error, so use the "||" to
let it always be true.

[YOCTO #2095]

(From OE-Core rev: 7893e74311e53882d8f93ecb95a6bd9f5b14651e)

Signed-off-by: Robert Yang <liezhi.yang@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>