Wizard: Remove redundant code, fix addItem

Removed redundant code and updated `addItem` to check for duplicate arguments in both required and non-required list.

src/Components/CreateImageWizard/ChippingInput.tsx

@@ -50,19 +50,19 @@ const ChippingInput = ({
   };
 
   const addItem = (value: string) => {
-    if (validator(value) && !list?.includes(value)) {
-      dispatch(addAction(value));
-      setInputValue('');
-      setErrorText('');
-    }
-
-    if (list?.includes(value)) {
+    if (list?.includes(value) || requiredList?.includes(value)) {
       setErrorText(`${item} already exists.`);
+      return;
     }
 
     if (!validator(value)) {
       setErrorText('Invalid format.');
+      return;
     }
+
+    dispatch(addAction(value));
+    setInputValue('');
+    setErrorText('');
   };
 
   const handleKeyDown = (e: React.KeyboardEvent, value: string) => {

src/Components/CreateImageWizard/steps/Kernel/components/KernelArguments.tsx

@@ -35,17 +35,13 @@ const KernelArguments = () => {
     oscapProfileInfo?.kernel?.append?.split(' ').includes(arg)
   );
 
-  const notRequiredByOpenSCAP = kernelAppend.filter(
-    (arg) => !oscapProfileInfo?.kernel?.append?.split(' ').includes(arg)
-  );
-
   return (
     <FormGroup isRequired={false} label="Append">
       <ChippingInput
         ariaLabel="Add kernel argument"
         placeholder="Add kernel argument"
         validator={isKernelArgumentValid}
-        list={notRequiredByOpenSCAP}
+        list={kernelAppend.filter((arg) => !requiredByOpenSCAP.includes(arg))}
         requiredList={requiredByOpenSCAP}
         item="Kernel argument"
         addAction={addKernelArg}