remoteproc: qcom_q6v5_adsp: Fix a NULL vs IS_ERR() check in adsp_alloc_memory_region()

The devm_ioremap_resource_wc() function never returns NULL, it returns
error pointers.  Update the check to match.

Fixes: c70b9d5 ("remoteproc: qcom: Use of_reserved_mem_region_* functions for "memory-region"")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Link: https://lore.kernel.org/r/6d6b1b0fb6a61b5155a640507217fd7e658858cf.1764427595.git.dan.carpenter@linaro.org
Signed-off-by: Bjorn Andersson <andersson@kernel.org>

Author: Dan Carpenter

drivers/remoteproc/qcom_q6v5_adsp.c

@@ -637,9 +637,10 @@ static int adsp_alloc_memory_region(struct qcom_adsp *adsp)
 	adsp->mem_phys = adsp->mem_reloc = res.start;
 	adsp->mem_size = resource_size(&res);
 	adsp->mem_region = devm_ioremap_resource_wc(adsp->dev, &res);
-	if (!adsp->mem_region) {
+	if (IS_ERR(adsp->mem_region)) {
 		dev_err(adsp->dev, "unable to map memory region: %pR\n", &res);
-		return -EBUSY;
+		return PTR_ERR(adsp->mem_region);
+
 	}
 
 	return 0;