[llvm-exegesis] Use ExitOnErr instead of manually logging and exiting

This patch removes an explicit use of dbgs() and exit when logging an
error to explicitly use ExitOnErr as this is the canonical way to do
this within exegesis.

Author: boomanaiden154

llvm/tools/llvm-exegesis/llvm-exegesis.cpp

@@ -423,10 +423,9 @@ static void runBenchmarkConfigurations(
         if (Err) {
           // Errors from executing the snippets are fine.
           // All other errors are a framework issue and should fail.
-          if (!Err.isA<SnippetExecutionFailure>()) {
-            llvm::errs() << "llvm-exegesis error: " << toString(std::move(Err));
-            exit(1);
-          }
+          if (!Err.isA<SnippetExecutionFailure>())
+            ExitOnErr(std::move(Err));
+
           BenchmarkResult.Error = toString(std::move(Err));
         }
         AllResults.push_back(std::move(BenchmarkResult));