treewide: Drop most cases of `sizeof(struct ...)`

Spelling out the struct type name hurts readability and introduces
opportunities for bugs to happen when the pointer variable type is
changed but the corresponding sizeof is (are) not.

Tested: `make CONFIG_EVERYTHING=yes CONFIG_JLINK_SPI=no VERSION=none -j`
with and without this patch; the flashrom executable does not change.

flashrom-stable: Applied partially.

Change-Id: Icc0b60ca6ef9f5ece6ed2a0e03600bb6ccd7dcc6
Signed-off-by: Angel Pons <th3fanbus@gmail.com>
Original-Reviewed-on: https://review.coreboot.org/c/flashrom/+/55266
Original-Reviewed-by: Nico Huber <nico.h@gmx.de>
Original-Reviewed-by: Edward O'Callaghan <quasisec@chromium.org>
Reviewed-on: https://review.coreboot.org/c/flashrom-stable/+/71371
Reviewed-by: Nico Huber <nico.h@gmx.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/physmap.c b/physmap.c
index 72d5899..6c36814 100644
--- a/physmap.c
+++ b/physmap.c
@@ -292,7 +292,7 @@
 	}
 
 	if (autocleanup) {
-		struct undo_physmap_data *d = malloc(sizeof(struct undo_physmap_data));
+		struct undo_physmap_data *d = malloc(sizeof(*d));
 		if (d == NULL) {
 			msg_perr("%s: Out of memory!\n", __func__);
 			physunmap_unaligned(virt_addr, len);