fs/ntfs3: Remove unnecessary condition checking from ntfs_file_read_iter

This check will be also performed in generic_file_read_iter() so we do
not want to check this two times in a row.

This was founded with Smatch
	fs/ntfs3/file.c:803 ntfs_file_read_iter()
	warn: unused return: count = iov_iter_count()
Signed-off-by: Kari Argillander <kari.argillander@gmail.com>
Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>

fs/ntfs3/file.c

@@ -793,8 +793,6 @@ int ntfs3_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
 
 static ssize_t ntfs_file_read_iter(struct kiocb *iocb, struct iov_iter *iter)
 {
-	ssize_t err;
-	size_t count = iov_iter_count(iter);
 	struct file *file = iocb->ki_filp;
 	struct inode *inode = file->f_mapping->host;
 	struct ntfs_inode *ni = ntfs_i(inode);
@@ -823,9 +821,7 @@ static ssize_t ntfs_file_read_iter(struct kiocb *iocb, struct iov_iter *iter)
 		return -EOPNOTSUPP;
 	}
 
-	err = count ? generic_file_read_iter(iocb, iter) : 0;
-
-	return err;
+	return generic_file_read_iter(iocb, iter);
 }
 
 /*