btrfs-progs: tests: Avoid printing useless warning in fsck tests

btrfs-progs: tests: Avoid printing useless warning in fsck tests

002-bad-transid outout 'transid verify failed' message in screen
which is just a warning in btrfs-image in normal condition of this
test.

This patch move above warning into $RESULTS, to:
1: Avoid trouble screen output
2: Let user known detail if other error happened in btrfs-image

Before patch:
  # ./fsck-tests.sh
    [TEST]   001-bad-file-extent-bytenr
    [TEST]   002-bad-transid
  parent transid verify failed on 29360128 wanted 9 found 755944791
  parent transid verify failed on 29360128 wanted 9 found 755944791
  Ignoring transid failure
    [TEST]   003-shift-offsets
    [TEST]   004-no-dir-index
  ...

After patch:
  # ./fsck-tests.sh
  [TEST]   001-bad-file-extent-bytenr
  [TEST]   002-bad-transid
  [TEST]   003-shift-offsets
  [TEST]   004-no-dir-index
  ...

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>