f2fs: speed up gc_urgent mode with SSR

commit b3a97a2a9a7b2d50bcf13d32857cd6f5695c6b65 upstream.

This patch activates SSR in gc_urgent mode.

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Git-commit: 55828d6e
Git-repo: https://android.googlesource.com/kernel/common.git


Signed-off-by: Sahitya Tummala <stummala@codeaurora.org>