Fix a memory leak when trying to open a non-existing file

https://bugzilla.redhat.com/show_bug.cgi?id=1914716
11 jobs for fix-memleak-in-fccat in 9 minutes and 5 seconds (queued for 2 seconds)
Status Name Job ID Coverage
  Build
passed meson android arm64 fedora #13081385

00:01:47

passed meson macos #13081383
gst-macos-10.15

00:03:19

failed meson-mingw-w64-build #13081380
allowed to fail

00:03:38

manual meson msys2 #13081384
docker windows 1809 allowed to fail manual
passed meson-shared-build #13081378

00:05:59

passed meson-static-build #13081379

00:06:53

passed meson vs2017 amd64 #13081381
docker windows 1809

00:01:19

passed meson vs2017 x86 #13081382
docker windows 1809

00:01:16

passed mingw-build #13081377

00:07:37

passed shared-build #13081375

00:09:05

passed static-build #13081376

00:07:54

 
Name Stage Failure
failed
meson-mingw-w64-build Build
mktexfmt [INFO]: exiting with status 0
ninja: build stopped: subcommand failed.
Uploading artifacts for failed job
Uploading artifacts...
build-*/meson-logs/*txt: found 1 matching files and directories

WARNING: prefix-*: no matching files
Uploading artifacts as "archive" to coordinator... ok
id=13081380 responseStatus=201 Created token=JbnVLpjA
Cleaning up file based variables
ERROR: Job failed: exit code 1