f2fs: call f2fs_handle_critical_error() to set cp_error flag

f2fs: call f2fs_handle_critical_error() to set cp_error flag

f2fs_handle_page_eio() is the only left place we set CP_ERROR_FLAG
directly, it missed to update superblock.s_stop_reason, let's
call f2fs_handle_critical_error() instead to fix that.

Introduce STOP_CP_REASON_READ_{META,NODE,DATA} stop_cp_reason enum
variable to indicate which kind of data we failed to read.

Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>