autotools: don't output the full config.log on configure failure
The config.log written by autoconf includes many pages of useless output,
followed by an obfuscated error message, and then more pages of every variable
that's been set. It's only understandable if you're well versed in how autoconf
behaves, and often in simple failure modes doesn't actually make it clear what
the problem was.
Instead of outputting the whole config.log to the console when do_configure()
fails, use bbfatal_log so the human-readable configure output (not the
config.log) is shown to the user, and tell the user where config.log can be
found if they need it.
[ YOCTO #8856 ]
Signed-off-by: Ross Burton <ross.burton@intel.com>
