[PATCH 0/2] fstests: fix test issue of xfs/157

[Zorro Lang <zlang@kernel.org>]

xfs/157 started to fail since 2f7e1b8a6f09 ("xfs/157,xfs/547,xfs/548: switch to
using _scratch_mkfs_sized") was merged.

  FSTYP         -- xfs (non-debug)
  PLATFORM      -- Linux/x86_64
  MKFS_OPTIONS  -- -f -m rmapbt=1 /dev/sda3
  MOUNT_OPTIONS -- -o context=system_u:object_r:root_t:s0 /dev/sda3 /mnt/scratch

  xfs/157 7s ... - output mismatch (see /root/git/xfstests/results//xfs/157.out.bad)
      --- tests/xfs/157.out       2024-11-01 01:05:03.664543576 +0800  
      +++ /root/git/xfstests/results//xfs/157.out.bad     2024-11-01 02:56:47.994007900 +0800
      @@ -6,10 +6,10 @@
       label = "oldlabel"
       label = "newlabel"
       S3: Check that setting with rtdev works
      -label = "oldlabel"
      +label = ""
       label = "newlabel"
       S4: Check that setting with rtdev + logdev works
      ...
      (Run 'diff -u /root/git/xfstests/tests/xfs/157.out /root/git/xfstests/results//xfs/157.out.bad'  to see the entire diff)
  Ran: xfs/157
  Failures: xfs/157
  Failed 1 of 1 tests

Before that change, the _scratch_mkfs can drop "rmapbt=1" option from $MKFS_OPTIONS,
only keep the "-L label" option. That's why this test never failed before. To fix
this failure, this patchset does:

The [PATCH 1/2] helps _scratch_mkfs_sized to support extra argument, then the
extra argument can be sent to _scratch_mkfs, which will try to "protect"
the extra argument from being dropped.

The [PATCH 2/2] invokes the new _scratch_mkfs_sized in xfs/157 to fix the
test failure of it.

Thanks,
Zorro