remoteproc: qcom_wcnss: Fix NULL vs IS_ERR() bug in wcnss_alloc_memory_region()

The devm_ioremap_resource_wc() function never returns NULL, it returns
error pointers.  Update the checking 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/09a43da41ee277a80a3265348831e747f7b62620.1764427595.git.dan.carpenter@linaro.org
Signed-off-by: Bjorn Andersson <andersson@kernel.org>

Author: Dan Carpenter

drivers/remoteproc/qcom_wcnss.c

@@ -538,9 +538,9 @@ static int wcnss_alloc_memory_region(struct qcom_wcnss *wcnss)
 	wcnss->mem_phys = wcnss->mem_reloc = res.start;
 	wcnss->mem_size = resource_size(&res);
 	wcnss->mem_region = devm_ioremap_resource_wc(wcnss->dev, &res);
-	if (!wcnss->mem_region) {
+	if (IS_ERR(wcnss->mem_region)) {
 		dev_err(wcnss->dev, "unable to map memory region: %pR\n", &res);
-		return -EBUSY;
+		return PTR_ERR(wcnss->mem_region);
 	}
 
 	return 0;