mxdmac->channel was unsigned, so check (imxdmac->channel < 0) for
failed imx_dma_request_by_prio() made no sence.  Explicitly check
signed values.
Also, fix uninitialzed use of ret.
Signed-off-by: Vasiliy Kulikov <segooon@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
 
                imxdmac->imxdma_channel = imx_dma_request_by_prio("dmaengine",
                                DMA_PRIO_MEDIUM);
-               if (imxdmac->channel < 0)
+               if ((int)imxdmac->channel < 0) {
+                       ret = -ENODEV;
                        goto err_init;
+               }
 
                imx_dma_setup_handlers(imxdmac->imxdma_channel,
                       imxdma_irq_handler, imxdma_err_handler, imxdmac);