llvm_report_error already prints "LLVM ERROR:". So stop reporting errors like "LLVM ERROR: llvm: error:" or "LLVM ERROR: ERROR:".

llvm-svn: 77971
diff --git a/llvm/lib/ExecutionEngine/Interpreter/Execution.cpp b/llvm/lib/ExecutionEngine/Interpreter/Execution.cpp
index b351ba2..8d21d1f 100644
--- a/llvm/lib/ExecutionEngine/Interpreter/Execution.cpp
+++ b/llvm/lib/ExecutionEngine/Interpreter/Execution.cpp
@@ -644,7 +644,7 @@
 }
 
 void Interpreter::visitUnreachableInst(UnreachableInst &I) {
-  llvm_report_error("ERROR: Program executed an 'unreachable' instruction!");
+  llvm_report_error("Program executed an 'unreachable' instruction!");
 }
 
 void Interpreter::visitBranchInst(BranchInst &I) {