[PWGCF] adjust conditional statement

[hernasab]

No description provided.

[github-actions]

O2 linter results: ❌ 0 errors, ⚠️ 0 warnings, 🔕 0 disabled

[alibuild]

Error while checking build/O2Physics/code-check for 4dff0d0 at 2026-07-13 03:49:

## sw/BUILD/O2Physics-code-check-latest/log
--
========== List of issues found ==========
++ echo 'Found 2 errors and 6 warnings.'
Found 2 errors and 6 warnings.
++ [[ 2 -gt 0 ]]
++ cat /sw/BUILD/f201d057b7e6f97522c296c20b9730294b1d955c/O2Physics-code-check/errors.txt
PWGCF/Flow/Tasks/flowZdcTask.cxx:55:78: error: macro argument should be enclosed in parentheses [bugprone-macro-parentheses,-warnings-as-errors]
PWGCF/Flow/Tasks/flowZdcTask.cxx:57:8: error: constructor does not initialize these fields: ccdb [cppcoreguidelines-pro-type-member-init,-warnings-as-errors]
++ [[ 6 -gt 0 ]]
++ cat /sw/BUILD/f201d057b7e6f97522c296c20b9730294b1d955c/O2Physics-code-check/warnings.txt
PWGCF/Flow/Tasks/flowZdcTask.cxx:545:102: warning: statement should be inside braces [readability-braces-around-statements]
PWGCF/Flow/Tasks/flowZdcTask.cxx:653:104: warning: statement should be inside braces [readability-braces-around-statements]
PWGCF/Flow/Tasks/flowZdcTask.cxx:655:104: warning: statement should be inside braces [readability-braces-around-statements]
PWGCF/Flow/Tasks/flowZdcTask.cxx:657:104: warning: statement should be inside braces [readability-braces-around-statements]
PWGCF/Flow/Tasks/flowZdcTask.cxx:659:102: warning: statement should be inside braces [readability-braces-around-statements]
PWGCF/Flow/Tasks/flowZdcTask.cxx:661:102: warning: statement should be inside braces [readability-braces-around-statements]
++ [[ 2 -gt 0 ]]
++ exit 1
--

Full log here.