btrfs: use %pe for error code output

During an interrupted mount, I got the following messages:

 workqueue: Failed to create a rescuer kthread for wq "btrfs-qgroup-rescan": -EINTR
 BTRFS error (device dm-3): open_ctree failed: -12

Workqueue code is outputting a human readable error string, meanwhile
we're still using a numeric error code.

So follow the workqueue code to use "%pe" format, which will
automatically convert an error pointer to the human readable string.

However this is a minor pitfall, if the return value is not an error
code, e.g. a positive number, "%pe" with "ERR_PTR(ret)" will output the
pointer as a hash value, e.g.:

 ret=1 %pe out=0000000019414716
 ret=-22 %pe out=-EINVAL

So we should not use this "%pe" output for callsites that are known to
return positive values.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

0 files changed, 0 insertions, 0 deletions