[LV] Use OrigLoop instead of induction to get function. (NFC)

Upcoming changes will result in Induction not being set/used in some
cases. Use OrigLoop to get the function instead.

Author: fhahn

llvm/lib/Transforms/Vectorize/LoopVectorize.cpp

@@ -8595,7 +8595,8 @@ void EpilogueVectorizerMainLoop::printDebugTracesAtStart() {
 
 void EpilogueVectorizerMainLoop::printDebugTracesAtEnd() {
   DEBUG_WITH_TYPE(VerboseDebug, {
-    dbgs() << "intermediate fn:\n" << *Induction->getFunction() << "\n";
+    dbgs() << "intermediate fn:\n"
+           << *OrigLoop->getHeader()->getParent() << "\n";
   });
 }
 
@@ -8793,7 +8794,7 @@ void EpilogueVectorizerEpilogueLoop::printDebugTracesAtStart() {
 
 void EpilogueVectorizerEpilogueLoop::printDebugTracesAtEnd() {
   DEBUG_WITH_TYPE(VerboseDebug, {
-    dbgs() << "final fn:\n" << *Induction->getFunction() << "\n";
+    dbgs() << "final fn:\n" << *OrigLoop->getHeader()->getParent() << "\n";
   });
 }