[PATCH] pstore/platform: build fix when crypto API are disabled

[Matteo Croce]

From: Matteo Croce <mcr...@microsoft.com>

When building a kernel with CONFIG_PSTORE=y and CONFIG_CRYPTO not set,
a build error happens:

    ld: fs/pstore/platform.o: in function `pstore_dump':
    platform.c:(.text+0x3f9): undefined reference to `crypto_comp_compress'
    ld: fs/pstore/platform.o: in function `pstore_get_backend_records':
    platform.c:(.text+0x784): undefined reference to `crypto_comp_decompress'

This because some pstore code uses crypto_comp_(de)compress
regardless of the CONFIG_CRYPTO status.
Fix it by wrapping the (de)compress usage by IS_ENABLED(CONFIG_PSTORE_COMPRESS)

Signed-off-by: Matteo Croce <mcr...@microsoft.com>
---
 fs/pstore/platform.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
index a9e297eefdff..6022d8359f96 100644
--- a/fs/pstore/platform.c
+++ b/fs/pstore/platform.c
@@ -436,7 +436,7 @@ static void pstore_dump(struct kmsg_dumper *dumper,
                                          dst_size, &dump_size))
                        break;
 
-               if (big_oops_buf) {
+               if (IS_ENABLED(CONFIG_PSTORE_COMPRESS) && big_oops_buf) {
                        zipped_len = pstore_compress(dst, psinfo->buf,
                                                header_size + dump_size,
                                                psinfo->bufsize);
@@ -668,7 +668,7 @@ static void decompress_record(struct pstore_record *record)
        int unzipped_len;
        char *unzipped, *workspace;
 
-       if (!record->compressed)
+       if (!IS_ENABLED(CONFIG_PSTORE_COMPRESS) || !record->compressed)
                return;
 
        /* Only PSTORE_TYPE_DMESG support compression. */
-- 
2.26.2