KVM: Remove obsolete comment about locking for kvm_io_bus_read/write

Nobody is actually calling these functions with slots_lock held, The
srcu_dereference() in kvm_io_bus_read/write() precisely communicates
both what is being protected, and what provides the protection. so the
comments are no longer needed

Suggested-by: Sean Christopherson <[email protected]>
Signed-off-by: Li RongQing <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Sean Christopherson <[email protected]>

Author: lrq-max

virt/kvm/kvm_main.c

@@ -5765,7 +5765,6 @@ static int __kvm_io_bus_write(struct kvm_vcpu *vcpu, struct kvm_io_bus *bus,
 	return -EOPNOTSUPP;
 }
 
-/* kvm_io_bus_write - called under kvm->slots_lock */
 int kvm_io_bus_write(struct kvm_vcpu *vcpu, enum kvm_bus bus_idx, gpa_t addr,
 		     int len, const void *val)
 {
@@ -5786,7 +5785,6 @@ int kvm_io_bus_write(struct kvm_vcpu *vcpu, enum kvm_bus bus_idx, gpa_t addr,
 }
 EXPORT_SYMBOL_GPL(kvm_io_bus_write);
 
-/* kvm_io_bus_write_cookie - called under kvm->slots_lock */
 int kvm_io_bus_write_cookie(struct kvm_vcpu *vcpu, enum kvm_bus bus_idx,
 			    gpa_t addr, int len, const void *val, long cookie)
 {
@@ -5836,7 +5834,6 @@ static int __kvm_io_bus_read(struct kvm_vcpu *vcpu, struct kvm_io_bus *bus,
 	return -EOPNOTSUPP;
 }
 
-/* kvm_io_bus_read - called under kvm->slots_lock */
 int kvm_io_bus_read(struct kvm_vcpu *vcpu, enum kvm_bus bus_idx, gpa_t addr,
 		    int len, void *val)
 {