Move error handling to Inflate class

Every call wants this check so this should be done inside the class.

kasmweb/core/inflator.js

@@ -37,6 +37,10 @@ export default class Inflate {
 
         inflate(this.strm, 0); // Flush argument not used.
 
+        if (this.strm.next_out != expected) {
+            throw new Error("Incomplete zlib block");
+        }
+
         return new Uint8Array(this.strm.output.buffer, 0, this.strm.next_out);
     }