staging: gasket: remove null ptr check before kfree

Remove null ptr check before kfree because kfree is null ptr safe.
Issue found by checkpatch.
Signed-off-by: Sumit Kumar <sumit686215@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/gasket/gasket_page_table.c

@@ -1328,10 +1328,8 @@ int gasket_alloc_coherent_memory(struct gasket_dev *gasket_dev, u64 size,
 				  num_pages * PAGE_SIZE, mem, handle);
 	}
 
-	if (gasket_dev->page_table[index]->coherent_pages) {
 	kfree(gasket_dev->page_table[index]->coherent_pages);
 	gasket_dev->page_table[index]->coherent_pages = NULL;
-	}
 	gasket_dev->page_table[index]->num_coherent_pages = 0;
 	return -ENOMEM;
 }