PSOutputDev: Fix memory leak on broken files

oss-fuzz/29201
7 jobs for t3String in 6 minutes and 1 second (queued for 2 seconds)
Status Job ID Name Coverage
  Build
passed #6426096
build

00:06:01

passed #6426101
build_android

00:00:52

passed #6426097
build_clang_libcpp

00:05:26

passed #6426100
build_clazy

00:05:14

passed #6426099
build_mingw64_fedora

00:03:16

passed #6426098
build_ubuntu_16_04

00:03:07

passed #6426095
clang_format

00:01:41