translate-all: remove redundant !tcg_enabled check in dump_exec_info

This check is redundant because it is already performed by the only
caller of dump_exec_info -- the caller was updated by b7da97eef
("monitor: Check whether TCG is enabled before running the "info jit"
code").

Checking twice wouldn't necessarily be too bad, but here the check also
returns with tb_lock held. So we can either do the check before tb_lock is
acquired, or just get rid of it. Given that it is redundant, I am going
for the latter option.

Signed-off-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
