Fix two regressions in ext4, one report by syzkaller[1], and reported by multiple users (and tracked by regzbot[2]). [1] https://syzkaller.appspot.com/bug?extid=4acc7d910e617b360859 [2] https://linux-regtracking.leemhuis.info/regzbot/regression/ZIauBR7YiV3rVAHL@glitch/