libexif: Avoid buffer overflow due to compiler optimization

Modify an arguments size check and decrease so that the
likelihood of the compiler removing it as part of
optimizations is low.
The arguments check must always be triggered to avoid
potential buffer overflows.

Bug: 159625731
Test: run sts-engbuild-no-spl-lock -m StsHostTestCases --test
android.security.sts.Poc20_08#testPocBug_159625731

Change-Id: I6f1b24a699c307b59e51dc0e22f4ed21f4b99feb
Merged-In: I6f1b24a699c307b59e51dc0e22f4ed21f4b99feb
1 file changed