staging: erofs: avoid opened loop codes

Use __GFP_NOFAIL to avoid opened loop codes in z_erofs_vle_unzip().

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Reviewed-by: Gao Xiang <gaoxiang25@huawei.com>
Link: https://lore.kernel.org/r/20190716094422.110805-1-yuchao0@huawei.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>