[CodeGen] Remove special case of printing subRegIdx from MachineInstr::print

Support in MachineOperand has been added in r320209. No need to special
case this anymore.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@322542 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed