erofs: simplify erofs_xattr_generic_get()

erofs_xattr_generic_get() won't be called from xattr handlers other than
user/trusted/security xattr handler, and thus there's no need of extra
checking.

Signed-off-by: Jingbo Xu <jefflexu@linux.alibaba.com>
Link: https://lore.kernel.org/r/20230330082910.125374-4-jefflexu@linux.alibaba.com
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Reviewed-by: Yue Hu <huyue2@coolpad.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>

fs/erofs/xattr.c

@@ -432,20 +432,9 @@ static int erofs_xattr_generic_get(const struct xattr_handler *handler,
 				   struct dentry *unused, struct inode *inode,
 				   const char *name, void *buffer, size_t size)
 {
-	struct erofs_sb_info *const sbi = EROFS_I_SB(inode);
-
-	switch (handler->flags) {
-	case EROFS_XATTR_INDEX_USER:
-		if (!test_opt(&sbi->opt, XATTR_USER))
-			return -EOPNOTSUPP;
-		break;
-	case EROFS_XATTR_INDEX_TRUSTED:
-		break;
-	case EROFS_XATTR_INDEX_SECURITY:
-		break;
-	default:
-		return -EINVAL;
-	}
+	if (handler->flags == EROFS_XATTR_INDEX_USER &&
+	    !test_opt(&EROFS_I_SB(inode)->opt, XATTR_USER))
+		return -EOPNOTSUPP;
 
 	return erofs_getxattr(inode, handler->flags, name, buffer, size);
 }