bugfix: when branchCommit failed,it will trigger retry of multi-tc and throw npe

[slievrly]

Signed-off-by: slievrly slievrly@163.com

Ⅰ. Describe what this PR did

bugfix: when branchCommit failed,it will trigger retry of multi-tc and throw npe

Ⅱ. Does this pull request fix one issue?

fix #1841

Ⅲ. Why don't you add test cases (unit test/integration test)?

Ⅳ. Describe how to verify it

Ⅴ. Special notes for reviews

[codecov-io]

Codecov Report

Merging #1845 into develop will increase coverage by 0.02%.
The diff coverage is 50%.

@@              Coverage Diff              @@
##             develop    #1845      +/-   ##
=============================================
+ Coverage      55.01%   55.04%   +0.02%     
  Complexity      2353     2353              
=============================================
  Files            422      422              
  Lines          14275    14279       +4     
  Branches        1713     1712       -1     
=============================================
+ Hits            7854     7860       +6     
- Misses          5687     5688       +1     
+ Partials         734      731       -3

Impacted Files	Coverage Δ	Complexity Δ
.../java/io/seata/server/coordinator/DefaultCore.java	42.68% <0%> (ø)	26 <0> (ø)	⬇️
...va/io/seata/core/store/db/LogStoreDataBaseDAO.java	59.47% <100%> (+0.41%)	21 <0> (ø)	⬇️
...a/io/seata/core/store/db/LockStoreDataBaseDAO.java	53.71% <100%> (+0.84%)	20 <0> (ø)	⬇️
...o/seata/server/coordinator/DefaultCoordinator.java	49.19% <28.57%> (-0.4%)	27 <0> (ø)
...server/store/file/FileTransactionStoreManager.java	59.21% <0%> (+0.65%)	29% <0%> (ø)	⬇️

[zjinlei]

LGTM

[lightClouds917]

LGTM

[xingfudeshi]

LGTM