xfstests 228: suppress core dump message

xfstests 228: suppress core dump message

When running 228 with abrt on in rhel6, I was getting different
output due to a (core dumped) message on SIGXFSZ.  For some reason
I wasn't able to use sed to filter it, and just ulimit -c 0 didn't
suppress it either.

abrt sets the core pattern to:

"|/usr/libexec/abrt-hook-ccpp /var/spool/abrt %p %s %u %c""

which apparently allows core dumps even if ulimit -c is 0, due
to the pipe.

Temporarily changing the kernel's core pattern to just plain "core"
and setting ulimit -c to 0 does suppress it.  These are reset to
original values after the test is run.

Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
Reviewed-by: Christoph Hellwig <hch@lst.de>