macintosh: Fix warning comparing pointer to 0

Fix the following coccicheck warnings:
./drivers/macintosh/via-cuda.c:240:16-17: WARNING comparing pointer to 0
./drivers/macintosh/via-cuda.c:243:16-17: WARNING comparing pointer to
0, suggest !E
./drivers/macintosh/via-cuda.c:521:23-24: WARNING comparing pointer to 0
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220214010558.130201-1-yang.lee@linux.alibaba.com

drivers/macintosh/via-cuda.c

@@ -237,10 +237,10 @@ int __init find_via_cuda(void)
     const u32 *reg;
     int err;
 
-    if (vias != 0)
+    if (vias)
 	return 1;
     vias = of_find_node_by_name(NULL, "via-cuda");
-    if (vias == 0)
+    if (!vias)
 	return 0;
 
     reg = of_get_property(vias, "reg", NULL);
@@ -518,7 +518,7 @@ cuda_write(struct adb_request *req)
     req->reply_len = 0;
 
     spin_lock_irqsave(&cuda_lock, flags);
-    if (current_req != 0) {
+    if (current_req) {
 	last_req->next = req;
 	last_req = req;
     } else {