bcachefs: Fix starting copygc when already started

We can sometimes call bch2_dev_read_write() when the device is already
RW (in error paths).

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This commit is contained in:
Kent Overstreet 2019-05-24 14:45:33 -04:00 • committed by Kent Overstreet
commit 5884fddfe7