dmaengine: edma: Fix error return code in edma_alloc_chan_resources()

Fix to return a negative error code from the error handling
case instead of 0, as done elsewhere in this function.

Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>