KVM: x86/mmu: Drop a redundant remote TLB flush in kvm_zap_gfn_range()

Remove an unnecessary remote TLB flush in kvm_zap_gfn_range() now that
said function holds mmu_lock for write for its entire duration.  The
flush was added by the now-reverted commit to allow TDP MMU to flush while
holding mmu_lock for read, as the transition from write=>read required
dropping the lock and thus a pending flush needed to be serviced.

Fixes: 5a324c24b6 ("Revert "KVM: x86/mmu: Allow zap gfn range to operate under the mmu read lock"")
Cc: Maxim Levitsky <[email protected]>
Cc: Maciej S. Szmigiero <[email protected]>
Cc: Ben Gardon <[email protected]>
Signed-off-by: Sean Christopherson <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Paolo Bonzini <[email protected]>

arch/x86/kvm/mmu/mmu.c

@@ -5743,9 +5743,6 @@ void kvm_zap_gfn_range(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end)
 						end - 1, true, flush);
 			}
 		}
-		if (flush)
-			kvm_flush_remote_tlbs_with_address(kvm, gfn_start,
-							   gfn_end - gfn_start);
 	}
 
 	if (is_tdp_mmu_enabled(kvm)) {