media: atomisp: Remove unneeded null check

In ia_css_frame_map, the check of 'err' is unneeded to be done twice.

Link: https://lore.kernel.org/linux-media/20211110094910.67951-1-vulab@iscas.ac.cnSigned-off-by: Xu Wang <vulab@iscas.ac.cn>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

drivers/staging/media/atomisp/pci/runtime/frame/src/frame.c

@@ -168,7 +168,6 @@ int ia_css_frame_map(struct ia_css_frame **frame,
 	if (err)
 		return err;
 
-	if (!err) {
 	if (pgnr < ((PAGE_ALIGN(me->data_bytes)) >> PAGE_SHIFT)) {
 		dev_err(atomisp_dev,
 			"user space memory size is less than the expected size..\n");
@@ -186,7 +185,6 @@ int ia_css_frame_map(struct ia_css_frame **frame,
 
 	if (me->data == mmgr_NULL)
 		err = -EINVAL;
-	}
 
 error:
 	if (err) {