btrfs: return error value if create_io_em failed in cow_file_range

In cow_file_range(), create_io_em() may fail, but its return value is
not recorded.  Then return value may be 0 even it failed which is a
wrong behavior.

Let cow_file_range() return PTR_ERR(em) if create_io_em() failed.

Fixes: 6f9994dbabe5 ("Btrfs: create a helper to create em for IO")
CC: [email protected] # 4.11+
Signed-off-by: Su Yue <[email protected]>
Reviewed-by: Nikolay Borisov <[email protected]>
Signed-off-by: David Sterba <[email protected]>

0 files changed, 0 insertions, 0 deletions