[pg] Fix typo potentially leading to crash #13086

Job	Run time
Event File	3s
Build Erlang/OTP (64-bit)	9m 58s
Build Erlang/OTP (iOS)	6m 5s
Build Erlang/OTP (macOS)	12m 58s
Build Erlang/OTP (Windows)	17m 24s
Build Erlang/OTP (32-bit)	13m 27s
Build Erlang/OTP (cross-compile)	20m 57s
Build and check documentation	10m 50s
Build Erlang/OTP (Types and Flavors)	0s
Build Erlang/OTP (clang)	9m 7s
Run static analysis	10m 11s
Test Erlang/OTP (kernel)	1h 2m 37s
Release Erlang/OTP	0s
Test Erlang/OTP (system)	10m 33s
	3h 4m 10s

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