spl: spl_legacy: fix invalid offset in SPL_COPY_PAYLOAD_ONLY

This fixes the header offset calculation.

This issue was found on uniphier v7 SoCs with SPL.

Fixes: 06377c5a1f ("spl: spl_legacy: Fix NAND boot on OMAP3 BeagleBoard")
Signed-off-by: Dai Okamura <okamura.dai@socionext.com>
Reviewed-By: Michael Trimarchi <michael@amarulasolutions.com>
Acked-by: Michael Trimarchi <michael@amarulasolutions.com>
Link: https://lore.kernel.org/all/20221209114021.3074978-1-okamura.dai@socionext.com
Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
diff --git a/common/spl/spl_legacy.c b/common/spl/spl_legacy.c
index 4c7f446..16851c5 100644
--- a/common/spl/spl_legacy.c
+++ b/common/spl/spl_legacy.c
@@ -106,7 +106,7 @@
 		 * is set
 		 */
 		if (spl_image->flags & SPL_COPY_PAYLOAD_ONLY)
-			dataptr += sizeof(hdr);
+			dataptr += sizeof(*hdr);
 
 		load->read(load, dataptr, spl_image->size,
 			   (void *)(unsigned long)spl_image->load_addr);
@@ -116,7 +116,7 @@
 		lzma_len = LZMA_LEN;
 
 		/* dataptr points to compressed payload  */
-		dataptr = offset + sizeof(hdr);
+		dataptr = offset + sizeof(*hdr);
 
 		debug("LZMA: Decompressing %08lx to %08lx\n",
 		      dataptr, spl_image->load_addr);