x86/EPT: squash meaningless TLB flush

x86/EPT: squash meaningless TLB flush

ept_free_entry() gets called after a flush was already issued, if one is
necessary in the first place. That behavior is similar to NPT, which
also doesn't have any further flush in p2m_free_entry(). (Furthermore,
the function being recursive, in case of recursiveness way too many
flushes would have been issued.)

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>