MINOR: Fix a typo in `ColumnReader.cc` #3375

Job	Run time
C++ format check (c++)	51s
Docker debian11	17m 31s
Java 17 and clang++ on ubuntu-20.04	14m 28s
C++ format check (tools)	15s
Javadoc generation	1m 44s
Java 21 and clang++ on ubuntu-20.04	13m 54s
Java 17 and clang++ on ubuntu-22.04	15m 15s
Docker debian12	19m 8s
License Check	31s
Java 21 and clang++ on ubuntu-22.04	15m 30s
SIMD programming using C++ intrinsic functions on ubuntu-22.04	9m 19s
Docker ubuntu24	17m 18s
Java 17 and clang++ on macos-12	27m 18s
Docker fedora37	18m 31s
Java 21 and clang++ on macos-12	22m 6s
C++ General Test on Windows	5m 14s
Docker rocky9	18m 43s
Java 17 and clang++ on macos-13	23m 6s
C++ AVX512 Test on Windows	5m 4s
Java 21 and clang++ on macos-13	22m 32s
Java 17 and g++ on ubuntu-22.04	15m 30s
	4h 43m 48s

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