KVM: VMX: Prepend "MAX_" to MSR array size defines

Add "MAX" to the LOADSTORE and so called SHARED MSR defines to make it
more clear that the define controls the array size, as opposed to the
actual number of valid entries that are in the array.

No functional change intended.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200923180409.32255-3-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>