libsel4vmmplatsupport: Fix an off-by-one error

Previously, the 'end' of an IO port range was not inclusive. This would
result in a bug where one IO port whose value is the 'end' of a range
would be mistaken as being part of that range when it should not be.
This commit fixes it so that the 'end' of an IO port range is now
inclusive. Also harden the range overlap check.

libsel4vmmplatsupport/src/ioports.c

diff --git a/libsel4vmmplatsupport/src/ioports.c b/libsel4vmmplatsupport/src/ioports.c
index 1eb2e73..9bf80d6 100644
--- a/libsel4vmmplatsupport/src/ioports.c
+++ b/libsel4vmmplatsupport/src/ioports.c
@@ -102,7 +102,7 @@
     }
     /* ensure this range does not overlap */
     for (int i = 0; i < io_list->num_ioports; i++) {
-        if (io_list->ioports[i]->range.end > port->range.start && io_list->ioports[i]->range.start < port->range.end) {
+        if (io_list->ioports[i]->range.end >= port->range.start && io_list->ioports[i]->range.start <= port->range.end) {
             ZF_LOGE("Requested ioport range 0x%x-0x%x for %s overlaps with existing range 0x%x-0x%x for %s",
                     port->range.start, port->range.end, port->interface.desc ? port->interface.desc : "Unknown IO Port",
                     io_list->ioports[i]->range.start, io_list->ioports[i]->range.end,
@@ -130,7 +130,7 @@
     }
     io_list->alloc_addr += io_range->size;
     io_range->start = free_port_addr;
-    io_range->end = free_port_addr + io_range->size;
+    io_range->end = free_port_addr + io_range->size - 1;
     return 0;
 }