LU-10550 flr: resync RDONLY state FLR file

LU-10550 flr: resync RDONLY state FLR file

When some components are failed to resync due to various reasons,
those components will still have STALE bit set but the file statue may
become to RDONLY.

This patch makes resync RDONLY FLR file possible.

Signed-off-by: Bobi Jam <bobijam.xu@intel.com>
Change-Id: I2e3b518bb969aedd7f214e6b09b895079cab69ab
Reviewed-on: https://review.whamcloud.com/31010
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Jinshan Xiong <jinshan.xiong@intel.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>