btrfs: zstd: move zstd_parameters to the workspace

btrfs: zstd: move zstd_parameters to the workspace

Reduce stack consumption of zstd_compress_folios() by 40 bytes
(10*sizeof(int)) as we can store struct zstd_parameters in the workspace
that is reused for each call.

typedef struct {
	ZSTD_compressionParameters cParams;
	ZSTD_frameParameters fParams;
} ZSTD_parameters;

typedef struct {
    unsigned windowLog;
    unsigned chainLog;
    unsigned hashLog;
    unsigned searchLog;
    unsigned minMatch;
    unsigned targetLength;
    ZSTD_strategy strategy;
} ZSTD_compressionParameters;

typedef struct {
    int contentSizeFlag;
    int checksumFlag;
    int noDictIDFlag;
} ZSTD_frameParameters;

Signed-off-by: David Sterba <dsterba@suse.com>