lib: simplify 'processChunkSync'

According to the real logic codes, it seems no matter whether 'nread >=
kMaxLength' or not. We always close the 'self' stream first. So we can
shorten it by merging them into one sample.

PR-URL: #22802
Reviewed-By: Tobias Nießen <tniessen@tnie.de>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Weijia Wang <starkwang@126.com>

lib/zlib.js

@@ -527,14 +527,12 @@ function processChunkSync(self, chunk, flushFlag) {
   }
 
   self.bytesWritten = inputRead;
+  _close(self);
 
   if (nread >= kMaxLength) {
-    _close(self);
     throw new ERR_BUFFER_TOO_LARGE();
   }
 
-  _close(self);
-
   if (nread === 0)
     return Buffer.alloc(0);