RegAllocGreedy: Fix comment typo

Author: arsenm

llvm/lib/CodeGen/RegAllocGreedy.cpp

@@ -2427,7 +2427,7 @@ MCRegister RAGreedy::selectOrSplitImpl(const LiveInterval &VirtReg,
     } else
       return PhysReg;
   }
-  // Non emtpy NewVRegs means VirtReg has been split.
+  // Non empty NewVRegs means VirtReg has been split.
   if (!NewVRegs.empty())
     return 0;