bcachefs: Ignore unknown mount options

This makes mount option handling consistent with other filesystems -
options may be handled at different layers, so an option we don't know
about might not be intended for us.

Signed-off-by: Kent Overstreet <[e-mail]>

fs/bcachefs/opts.c

···
 			val = "0";
 		}
 
+		/* Unknown options are ignored: */
 		if (id < 0)
-			goto bad_opt;
+			continue;
 
 		if (!(bch2_opt_table[id].flags & OPT_MOUNT))
 			goto bad_opt;