[NFC] Format MachineVerifier.cpp to remove extra indentation (#111602)

Many structs in this class have the wrong indentation. To generate this
diff, I touched the first line of each struct and then ran `git
clang-format`. This will make blaming more difficult, but this
autoformatting is difficult to avoid triggering. I think it's best to
push this as one NFC PR.

Author: ellishg