Minor, remove unnecessary logging for valid erroneous case

It seems that it's normal for VirtualFile in this place to be invalid in this
way

idea/idea-analysis/src/org/jetbrains/kotlin/idea/decompiler/js/KotlinJavaScriptMetaFileDecompiler.kt

@@ -16,7 +16,6 @@
 
 package org.jetbrains.kotlin.idea.decompiler.js
 
-import com.intellij.openapi.diagnostic.Logger
 import com.intellij.openapi.vfs.VirtualFile
 import com.intellij.psi.FileViewProvider
 import com.intellij.psi.PsiManager
@@ -51,10 +50,6 @@ class KotlinJavaScriptMetaFileDecompiler : ClassFileDecompilers.Full() {
             KtDecompiledFile(provider, ::buildDecompiledTextFromJsMetadata)
         }
     }
-
-    companion object {
-        internal val LOG = Logger.getInstance(KotlinJavaScriptMetaFileDecompiler::class.java)
-    }
 }
 
 private val decompilerRendererForJS = DescriptorRenderer.withOptions { defaultDecompilerRendererOptions() }
@@ -125,9 +120,8 @@ sealed class KjsmFile {
             catch (e: IOException) {
                 // This is needed because sometimes we're given VirtualFile instances that point to non-existent .jar entries.
                 // Such files are valid (isValid() returns true), but an attempt to read their contents results in a FileNotFoundException.
-                // This looks like a platform issue, but we must still deal with it somehow here.
-                // Calling "refresh()" instead of catching an exception would be more correct, but is likely to degrade performance
-                KotlinJavaScriptMetaFileDecompiler.LOG.warn("Attempt to read non-existing file: $file", e)
+                // Note that although calling "refresh()" instead of catching an exception would seem more correct here,
+                // it's not always allowed and also is likely to degrade performance
                 null
             }
         }