[InstrProfiling] Emit runtime hook only once

[gulfem]

Summary

This patch fixes the issue about calling emitRuntimeHook() twice
when we need to unconditionally emit runtime hook as discussed in
https://reviews.llvm.org/rGd6aed77f0d19.

[phosek]

LGTM

llvm/lib/Transforms/Instrumentation/InstrProfiling.cpp

bool InstrProfiling::run(
   }
 
   if (!MadeChange)
     return false;
 
   emitVNodes();
   emitNameData();
 
-  // Emit runtime hook except for the cases where coverage is enabled on
-  // code that is eliminated by the front-end, e.g. unused functions with
-  // internal linkage, and the target does not require pulling in profile
-  // runtime.
-  if (containsProfilingIntrinsics(M) || !CoverageNamesVar || NeedsRuntimeHook)
+  // Emit runtime hook for the cases where the target does not unconditionally
+  // require pulling in profile runtime, and coverage is enabled on code that is
+  // not eliminated by the front-end, e.g. unused functions with internal
+  // linkage.
+  if (!NeedsRuntimeHook && containsProfilingIntrinsics(M))
     emitRuntimeHook();
 
   emitRegistration();
   emitUses();
   emitInitialization();
   return true;
 }