Fix overwrite-only under Zephyr
As reported by issue some #ifdefery was wrongly done, which broke
overwrite-only mode under Zephyr.
@@ -1523,7 +1523,7 @@ boot_swap_if_needed(int *out_swap_type)
/* If a partial swap was detected, complete it. */
if (bs.idx != BOOT_STATUS_IDX_0 || bs.state != BOOT_STATUS_STATE_0) {
-#if MCUBOOT_OVERWRITE_ONLY
+#ifdef MCUBOOT_OVERWRITE_ONLY
/* Should never arrive here, overwrite-only mode has no swap state. */
assert(0);
#else
@@ -1547,7 +1547,7 @@ boot_swap_if_needed(int *out_swap_type)
case BOOT_SWAP_TYPE_TEST:
case BOOT_SWAP_TYPE_PERM:
case BOOT_SWAP_TYPE_REVERT:
-#if MCUBOOT_OVERWRITE_ONLY
+#ifdef MCUBOOT_OVERWRITE_ONLY
rc = boot_copy_image(&bs);
#else
rc = boot_swap_image(&bs);
