doc/kvm: Fix wrong entry for KVM_CAP_X86_MSR_FILTER

The capability that exposes new ioctl KVM_X86_SET_MSR_FILTER to
userspace is specified incorrectly as the ioctl itself (instead of
KVM_CAP_X86_MSR_FILTER). This patch fixes it.

Fixes: 1a155254 ("KVM: x86: Introduce MSR filtering")
Reviewed-by: Alexander Graf <graf@amazon.de>
Signed-off-by: Siddharth Chandrasekaran <sidcha@amazon.de>
Message-Id: <20210503120059.9283-1-sidcha@amazon.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Documentation/virt/kvm/api.rst

@@ -4803,7 +4803,7 @@ KVM_PV_VM_VERIFY
 4.126 KVM_X86_SET_MSR_FILTER
 ----------------------------
 
-:Capability: KVM_X86_SET_MSR_FILTER
+:Capability: KVM_CAP_X86_MSR_FILTER
 :Architectures: x86
 :Type: vm ioctl
 :Parameters: struct kvm_msr_filter
@@ -6715,7 +6715,7 @@ accesses that would usually trigger a #GP by KVM into the guest will
 instead get bounced to user space through the KVM_EXIT_X86_RDMSR and
 KVM_EXIT_X86_WRMSR exit notifications.
 
-8.27 KVM_X86_SET_MSR_FILTER
+8.27 KVM_CAP_X86_MSR_FILTER
 ---------------------------
 
 :Architectures: x86