flashrom.c: extract operation only uses layout files

This change fixes a bug on handling the extract operation. The extract
operation reads out the layout regions to filenames corresponding to the
respective layout region names.  read_flash_to_file() does this work via
write_buf_to_include_args(). This change makes the call to
write_buf_to_file() optional as it is still required for -r (read
operation) but not for -x (extract operation).

BUG=b:209512852
TEST=flashrom -x

Fixes: commit ce983bccaab450d358854494f15c2d8a1846d56b
Change-Id: Ibc9a4e2966385863345f06662521d6d0e4685121
Signed-off-by: Daniel Campello <campello@chromium.org>
Reviewed-on: https://review.coreboot.org/c/flashrom/+/59921
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Edward O'Callaghan <quasisec@chromium.org>

1 files changed, 2 insertions, 1 deletions

diff --git a/flashrom.c b/flashrom.c
index bd34676f..dd443b93 100644
--- a/flashrom.c
+++ b/flashrom.c
@@ -1098,7 +1098,8 @@ int read_flash_to_file(struct flashctx *flash, const char *filename)
 		goto out_free;
 	}
 
-	ret = write_buf_to_file(buf, size, filename);
+	if (filename)
+		ret = write_buf_to_file(buf, size, filename);
 out_free:
 	free(buf);
 	msg_cinfo("%s.\n", ret ? "FAILED" : "done");