kernfs/file.c: remove redundant error return counter assignment

Since previous 'rc = -EINVAL;', rc value doesn't change, so not
necessary to re-assign it again.
Signed-off-by: Lin Feng <linf@wangsu.com>
Link: https://lore.kernel.org/r/20220617091746.206515-1-linf@wangsu.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fs/kernfs/file.c

@@ -484,7 +484,6 @@ static int kernfs_fop_mmap(struct file *file, struct vm_area_struct *vma)
 	 * It is not possible to successfully wrap close.
 	 * So error if someone is trying to use close.
 	 */
-	rc = -EINVAL;
 	if (vma->vm_ops && vma->vm_ops->close)
 		goto out_put;