Fix possible uninitialized value in test_utils.c

[afiskon]

Supress the following CLang warning:

warning: 2nd function call argument is an uninitialized value
[clang-analyzer-core.CallAndMessage]

[mkindahl]

LGTM.

[codecov]

Codecov Report

Merging #3787 (d1fe8e9) into master (4ff1bd3) will increase coverage by 0.17%.
The diff coverage is 96.57%.

@@            Coverage Diff             @@
##           master    #3787      +/-   ##
==========================================
+ Coverage   90.32%   90.49%   +0.17%     
==========================================
  Files         212      213       +1     
  Lines       37179    37753     +574     
==========================================
+ Hits        33581    34165     +584     
+ Misses       3598     3588      -10     

Impacted Files	Coverage Δ
src/chunk_data_node.c	98.98% <ø> (ø)
src/chunk_index.c	94.77% <ø> (ø)
src/compat/compat.h	94.28% <ø> (ø)
src/extension.c	88.77% <ø> (ø)
src/extension_utils.c	81.39% <ø> (ø)
src/hypertable_data_node.c	95.41% <ø> (ø)
src/loader/loader.c	91.94% <ø> (ø)
src/nodes/chunk_append/chunk_append.c	97.40% <ø> (ø)
src/nodes/chunk_append/exec.c	95.84% <ø> (ø)
src/nodes/chunk_append/explain.c	82.81% <ø> (ø)
... and 66 more

---

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 82656a6...d1fe8e9. Read the comment docs.