mm/mmap.c: replace IS_ERR and PTR_ERR with PTR_ERR_OR_ZERO

Author: Duan Jiong <duanj.fnst@cn.fujitsu.com>

Fix a coccinelle error regarding usage of IS_ERR and PTR_ERR instead of
PTR_ERR_OR_ZERO.

Signed-off-by: Duan Jiong 
Acked-by: Rik van Riel 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
---
 mm/mmap.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)
 
diff --git a/mm/mmap.c b/mm/mmap.c
index b1202cf..6cdec3a 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -2965,9 +2965,7 @@ int install_special_mapping(struct mm_struct *mm,
 	struct vm_area_struct *vma = _install_special_mapping(mm,
 			    addr, len, vm_flags, pages);
 
-	if (IS_ERR(vma))
-		return PTR_ERR(vma);
-	return 0;
+	return PTR_ERR_OR_ZERO(vma);
 }
 
 static DEFINE_MUTEX(mm_all_locks_mutex);