Revert "memory: Use canonical path component as the name"

This reverts commit b0225c2c0d89200a29dc3d0b59d2e87a79cbaeb8
(which breaks building with Xen enabled and also leaks memory).

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
diff --git a/include/exec/memory.h b/include/exec/memory.h
index 10f73d9..d165b27 100644
--- a/include/exec/memory.h
+++ b/include/exec/memory.h
@@ -162,6 +162,7 @@
     QTAILQ_HEAD(subregions, MemoryRegion) subregions;
     QTAILQ_ENTRY(MemoryRegion) subregions_link;
     QTAILQ_HEAD(coalesced_ranges, CoalescedMemoryRange) coalesced;
+    const char *name;
     uint8_t dirty_log_mask;
     unsigned ioeventfd_nb;
     MemoryRegionIoeventfd *ioeventfds;