Fix bug in flush.go that would cause persist manager to get stuck in idle state

[richardartoul]

No description provided.

[codecov]

Codecov Report

Merging #2007 into master will increase coverage by 2%.
The diff coverage is 0%.

@@            Coverage Diff            @@
##           master    #2007     +/-   ##
=========================================
+ Coverage    61.5%    63.6%     +2%     
=========================================
  Files        1118     1124      +6     
  Lines      106427   106753    +326     
=========================================
+ Hits        65477    67910   +2433     
+ Misses      36583    34492   -2091     
+ Partials     4367     4351     -16

Flag	Coverage Δ
#aggregator	79.7% <ø> (ø)	⬆️
#cluster	56.3% <ø> (ø)	⬆️
#collector	63.7% <ø> (ø)	⬆️
#dbnode	65% <0%> (+3.3%)	⬆️
#m3em	59.6% <ø> (+13.1%)	⬆️
#m3ninx	61.1% <ø> (-0.1%)	⬇️
#m3nsch	51.1% <ø> (ø)	⬆️
#metrics	17.7% <ø> (ø)	⬆️
#msg	74.7% <ø> (ø)	⬆️
#query	68.6% <ø> (ø)	⬆️
#x	75% <ø> (+6.9%)	⬆️

---

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Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 351e12d...e2e24b9. Read the comment docs.

[codecov]

Codecov Report

Merging #2007 into master will increase coverage by 2%.
The diff coverage is 0%.

@@            Coverage Diff            @@
##           master    #2007     +/-   ##
=========================================
+ Coverage    61.5%    63.6%     +2%     
=========================================
  Files        1118     1124      +6     
  Lines      106427   106753    +326     
=========================================
+ Hits        65477    67910   +2433     
+ Misses      36583    34492   -2091     
+ Partials     4367     4351     -16

Flag	Coverage Δ
#aggregator	79.7% <ø> (ø)	⬆️
#cluster	56.3% <ø> (ø)	⬆️
#collector	63.7% <ø> (ø)	⬆️
#dbnode	65% <0%> (+3.3%)	⬆️
#m3em	59.6% <ø> (+13.1%)	⬆️
#m3ninx	61.1% <ø> (-0.1%)	⬇️
#m3nsch	51.1% <ø> (ø)	⬆️
#metrics	17.7% <ø> (ø)	⬆️
#msg	74.7% <ø> (ø)	⬆️
#query	68.6% <ø> (ø)	⬆️
#x	75% <ø> (+6.9%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 351e12d...5dd6456. Read the comment docs.

[justinjc]