CID 991761: potential double close (and white space fix)

src/bin/chop.c

@@ -240,6 +240,7 @@ chop_file(int fdin, char *fname, off_t fsize)
 		}
 	}
 
-	// close up the last output file
+	// close up the last output file if it's still open
+	if (!open_next_file)
 		close(fdout);
 }