booutil: swap_scratch: Do not check sectors with compression

When compression is used, it allows for the secondary slot to be
smaller than the primary slot, therefore do not ensure that the
number of sectors in each slot are the same

Signed-off-by: Jamie McCrae <jamie.mccrae@nordicsemi.no>

boot/bootutil/src/swap_scratch.c

@@ -218,12 +218,14 @@ boot_slots_compatible(struct boot_loader_state *state)
 #endif
  }
 
+#ifndef MCUBOOT_DECOMPRESS_IMAGES
  if ((i != num_sectors_primary) ||
  (j != num_sectors_secondary) ||
  (primary_slot_sz != secondary_slot_sz)) {
  BOOT_LOG_WRN("Cannot upgrade: slots are not compatible");
  return 0;
  }
+#endif
 
  return 1;
 }