dmaengine fixes for v5.6-rc1

Fixes for:
 - Documentation build error fix
 - Fix dma_request_chan() error return
 - Remove unneeded conversion in idxd driver
 - Fix pointer check for dma_async_device_channel_register()
 - Fix slave-channel symlink cleanup
dmaengine: Cleanups for the slave <-> channel symlink support

No need to use goto to jump over the
return chan ? chan : ERR_PTR(-EPROBE_DEFER);
We can just revert the check and return right there.

Do not fail the channel request if the chan->name allocation fails, but
print a warning about it.

Change the dev_err to dev_warn if sysfs_create_link() fails as it is not
fatal.

Only attempt to remove the DMA_SLAVE_NAME symlink if it is created - or it
was attempted to be created.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20200131093859.3311-2-peter.ujfalusi@ti.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
1 file changed