remoteproc: core: Ensure error message is clear

Before this patch, the dma_alloc_coherent() failure path printed out:

  "dma_alloc_coherent err: 16760832"

... alluding to the Linux error code being 16760832, but seeing as
Linux error codes are all negative, this looks like a signed/unsigned
issue.  In fact, the message is trying to print the length of the
requested memory region.  Let's clear that up.

While we're at it, let's standardise the way 'len' is printed.  In
all other locations 'len' is in hex prefixed by a '0x' for clarity.
Signed-off-by: NLee Jones <lee.jones@linaro.org>
Signed-off-by: NBjorn Andersson <bjorn.andersson@linaro.org>

drivers/remoteproc/remoteproc_core.c

@@ -579,7 +579,7 @@ static int rproc_handle_carveout(struct rproc *rproc,
 		return -EINVAL;
 	}
 
-	dev_dbg(dev, "carveout rsc: da %x, pa %x, len %x, flags %x\n",
+	dev_dbg(dev, "carveout rsc: da %x, pa %x, len 0x%x, flags %x\n",
 			rsc->da, rsc->pa, rsc->len, rsc->flags);
 
 	carveout = kzalloc(sizeof(*carveout), GFP_KERNEL);
@@ -588,7 +588,8 @@ static int rproc_handle_carveout(struct rproc *rproc,
 
 	va = dma_alloc_coherent(dev->parent, rsc->len, &dma, GFP_KERNEL);
 	if (!va) {
-		dev_err(dev->parent, "dma_alloc_coherent err: %d\n", rsc->len);
+		dev_err(dev->parent,
+			"failed to allocate dma memory: len 0x%x\n", rsc->len);
 		ret = -ENOMEM;
 		goto free_carv;
 	}