sanitizer: Remove dead code in sancov.cc. [PR120581]

This is dead since COND_EXPR is always a SSA_NAME or a constant.

Bootstrapped and regtested on x86_64-pc-linux-gnu.

	PR sanitizer/120581

gcc/ChangeLog:

	* sancov.cc (sancov_pass): Remove dead code.

Signed-off-by: Kael Andrew Franco <kaelfandrew@gmail.com>