hw/xen: Use g_free instead of free and fix potential memory leaks

The wrong functions and the missing calls of g_free were reported
by cppcheck.

Signed-off-by: Stefan Weil <sw@weilnetz.de>
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
diff --git a/hw/xen/xen_pt_config_init.c b/hw/xen/xen_pt_config_init.c
index 01872db..8ccc2e4 100644
--- a/hw/xen/xen_pt_config_init.c
+++ b/hw/xen/xen_pt_config_init.c
@@ -1777,12 +1777,12 @@
         rc = reg->init(s, reg_entry->reg,
                        reg_grp->base_offset + reg->offset, &data);
         if (rc < 0) {
-            free(reg_entry);
+            g_free(reg_entry);
             return rc;
         }
         if (data == XEN_PT_INVALID_REG) {
             /* free unused BAR register entry */
-            free(reg_entry);
+            g_free(reg_entry);
             return 0;
         }
         /* set register value */