GUI: fix another cppcheck warning

src/gui/settings.cpp

@@ -1951,14 +1951,13 @@ bool FurnaceGUI::importLayout(String path) {
     fclose(f);
     return false;
   }
-  unsigned char* file=new unsigned char[len];
   if (fseek(f,0,SEEK_SET)<0) {
     perror("size error");
     lastError=fmt::sprintf("on get size: %s",strerror(errno));
     fclose(f);
-    delete[] file;
     return false;
   }
+  unsigned char* file=new unsigned char[len];
   if (fread(file,1,(size_t)len,f)!=(size_t)len) {
     perror("read error");
     lastError=fmt::sprintf("on read: %s",strerror(errno));