avoid malfunction when virFileResolveLink is applied to non-POSIX FS

The virFileResolveLink utility function relied on the POSIX guarantee
that stat.st_size of a symlink is the length of the value.  However,
on some types of file systems, it is invalid, so do not rely on it.
Use gnulib's areadlink module instead.
* bootstrap (modules): Add areadlink.
* src/util/util.c: Include "areadlink.h".
Let areadlink perform the readlink and malloc.
* configure.in (AC_CHECK_FUNCS): Remove readlink.  No need,
since it's presence is guaranteed by gnulib.

1 files changed, 1 insertions, 0 deletions

diff --git a/bootstrap b/bootstrap
index 667af4fc8..c07d85158 100755
--- a/bootstrap
+++ b/bootstrap
@@ -65,6 +65,7 @@ gnulib_tool=$GNULIB_SRCDIR/gnulib-tool
 <$gnulib_tool || exit
 
 modules='
+areadlink
 base64
 c-ctype
 close