tools: kwboot: Simplify code for aligning image header

Expression (hdrsz % KWBOOT_XM_BLKSZ) is non-zero therefore expression
(KWBOOT_XM_BLKSZ - hdrsz % KWBOOT_XM_BLKSZ) is always less than value
KWBOOT_XM_BLKSZ. So there is no need to add another modulo. Also rename
variable `offset` to `grow` which better describes what is stored in
this variable.

Signed-off-by: Pali Rohár <pali@kernel.org>
Reviewed-by: Marek Behún <marek.behun@nic.cz>
Reviewed-by: Stefan Roese <sr@denx.de>

diff --git a/tools/kwboot.c b/tools/kwboot.c
index 7fd28aa..adec4ec 100644 (file)
--- a/tools/kwboot.c
+++ b/tools/kwboot.c
@@ -1563,8 +1563,7 @@ kwboot_img_patch(void *img, size_t *size, int baudrate)
        }
 
        if (hdrsz % KWBOOT_XM_BLKSZ) {
-               size_t offset = (KWBOOT_XM_BLKSZ - hdrsz % KWBOOT_XM_BLKSZ) %
-                               KWBOOT_XM_BLKSZ;
+               size_t grow = KWBOOT_XM_BLKSZ - hdrsz % KWBOOT_XM_BLKSZ;
 
                if (is_secure) {
                        fprintf(stderr, "Cannot align image with secure header\n");
@@ -1572,7 +1571,7 @@ kwboot_img_patch(void *img, size_t *size, int baudrate)
                }
 
                kwboot_printv("Aligning image header to Xmodem block size\n");
-               kwboot_img_grow_hdr(img, size, offset);
+               kwboot_img_grow_hdr(img, size, grow);
        }
 
        hdr->checksum = kwboot_hdr_csum8(hdr) - csum;