[MLIR][OpenMP] - Fix translation of omp.target when private variables need cleaning up

This is a simple fix that ensures that the InsertPoint is properly fixed up
after we have translated the dealloc region of all privatized variables during
translation of omp.target from MLIR to LLVMIR.

Fix for #129202

Author: bhandarkar-pranav

mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp

@@ -4832,6 +4832,7 @@ convertOmpTarget(Operation &opInst, llvm::IRBuilderBase &builder,
             "failed to inline `dealloc` region of `omp.private` "
             "op in the target region");
       }
+      return builder.saveIP();
     }
 
     return InsertPointTy(exitBlock.get(), exitBlock.get()->end());