switch simple cases of fget_light to fdget

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/statfs.c b/fs/statfs.c
index 95ad5c0..f8e832e 100644
--- a/fs/statfs.c
+++ b/fs/statfs.c
@@ -87,12 +87,11 @@
 
 int fd_statfs(int fd, struct kstatfs *st)
 {
-	int fput_needed;
-	struct file *file = fget_light(fd, &fput_needed);
+	struct fd f = fdget(fd);
 	int error = -EBADF;
-	if (file) {
-		error = vfs_statfs(&file->f_path, st);
-		fput_light(file, fput_needed);
+	if (f.file) {
+		error = vfs_statfs(&f.file->f_path, st);
+		fdput(f);
 	}
 	return error;
 }