[llvm] [AMDGPU] Make use of getFunction and getMF. NFC. (PR #167872)

[Juan Manuel Martinez Caamaño via llvm-commits]

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@@ -55,7 +55,7 @@ void R600AsmPrinter::emitInstruction(const MachineInstr *MI) {
 
   StringRef Err;
   if (!STI.getInstrInfo()->verifyInstruction(*MI, Err)) {
-    LLVMContext &C = MI->getParent()->getParent()->getFunction().getContext();
+    LLVMContext &C = MI->getMF()->getFunction().getContext();
     C.emitError("Illegal instruction detected: " + Err);
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jmmartinez wrote:

```suggestion
  MI->emitGenericError("Illegal instruction detected: " + Err);
```

https://github.com/llvm/llvm-project/pull/167872