[PATCH -next] nvmem: Fix return value check in rmem_read()

[Wei Yongjun]

In case of error, the function memremap() returns NULL pointer
not ERR_PTR(). The IS_ERR() test in the return value check
should be replaced with NULL test.

Fixes: 5a3fa75a4d9c ("nvmem: Add driver to expose reserved memory as nvmem")
Reported-by: Hulk Robot <hul...@huawei.com>
Signed-off-by: Wei Yongjun <weiyongj...@huawei.com>
---
 drivers/nvmem/rmem.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/nvmem/rmem.c b/drivers/nvmem/rmem.c
index b11c3c974b3d..80cb187f1481 100644
--- a/drivers/nvmem/rmem.c
+++ b/drivers/nvmem/rmem.c
@@ -37,9 +37,9 @@ static int rmem_read(void *context, unsigned int offset,
         * but as of Dec 2020 this isn't possible on arm64.
         */
        addr = memremap(priv->mem->base, available, MEMREMAP_WB);
-       if (IS_ERR(addr)) {
+       if (!addr) {
                dev_err(priv->dev, "Failed to remap memory region\n");
-               return PTR_ERR(addr);
+               return -ENOMEM;
        }
 
        count = memory_read_from_buffer(val, bytes, &off, addr, available);