xl: free the libxl types contained in struct domain_config

xl: free the libxl types contained in struct domain_config

Resolves the following leaks found using "valgrind xl create -n ..."
(plus presumably others which didn't trigger because I have no devices
of that type)

[PATCH 10 of 16 of
 libxl: autogenerate type definitions and destructor functions]

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
==21241== 5 bytes in 1 blocks are definitely lost in loss record 1 of 6
==21241==    at 0x4022F0A: malloc (vg_replace_malloc.c:236)
==21241==    by 0x411B22F: strdup (in /lib/i686/cmov/libc-2.7.so)
==21241==    by 0x804E56B: parse_config_data (xl_cmdimpl.c:760)
==21241==    by 0x8056B04: create_domain (xl_cmdimpl.c:1357)
==21241==    by 0x8057ECE: main_create (xl_cmdimpl.c:3154)
==21241==    by 0x804B2FB: main (xl.c:76)
==21241==
==21241== 6 bytes in 1 blocks are definitely lost in loss record 2 of 6
==21241==    at 0x4022F0A: malloc (vg_replace_malloc.c:236)
==21241==    by 0x411B22F: strdup (in /lib/i686/cmov/libc-2.7.so)
==21241==    by 0x804DAAA: parse_config_data (xl_cmdimpl.c:586)
==21241==    by 0x8056B04: create_domain (xl_cmdimpl.c:1357)
==21241==    by 0x8057ECE: main_create (xl_cmdimpl.c:3154)
==21241==    by 0x804B2FB: main (xl.c:76)
==21241==
==21241== 24 bytes in 1 blocks are definitely lost in loss record 3 of 6
==21241==    at 0x4022F0A: malloc (vg_replace_malloc.c:236)
==21241==    by 0x411B22F: strdup (in /lib/i686/cmov/libc-2.7.so)
==21241==    by 0x804E51F: parse_config_data (xl_cmdimpl.c:754)
==21241==    by 0x8056B04: create_domain (xl_cmdimpl.c:1357)
==21241==    by 0x8057ECE: main_create (xl_cmdimpl.c:3154)
==21241==    by 0x804B2FB: main (xl.c:76)
==21241==
==21241== 27 bytes in 1 blocks are definitely lost in loss record 4 of 6
==21241==    at 0x4022F0A: malloc (vg_replace_malloc.c:236)
==21241==    by 0x411B22F: strdup (in /lib/i686/cmov/libc-2.7.so)
==21241==    by 0x804DF4A: parse_config_data (xl_cmdimpl.c:664)
==21241==    by 0x8056B04: create_domain (xl_cmdimpl.c:1357)
==21241==    by 0x8057ECE: main_create (xl_cmdimpl.c:3154)
==21241==    by 0x804B2FB: main (xl.c:76)
==21241==
==21241== 28 bytes in 1 blocks are definitely lost in loss record 5 of 6
==21241==    at 0x4022F0A: malloc (vg_replace_malloc.c:236)
==21241==    by 0x410C1A7: vasprintf (in /lib/i686/cmov/libc-2.7.so)
==21241==    by 0x40EE59A: asprintf (in /lib/i686/cmov/libc-2.7.so)
==21241==    by 0x804CA8B: init_nic_info (xl_cmdimpl.c:322)
==21241==    by 0x804E6FF: parse_config_data (xl_cmdimpl.c:791)
==21241==    by 0x8056B04: create_domain (xl_cmdimpl.c:1357)
==21241==    by 0x8057ECE: main_create (xl_cmdimpl.c:3154)
==21241==    by 0x804B2FB: main (xl.c:76)
==21241==
==21241== 44 bytes in 1 blocks are definitely lost in loss record 6 of 6
==21241==    at 0x4022F0A: malloc (vg_replace_malloc.c:236)
==21241==    by 0x411B22F: strdup (in /lib/i686/cmov/libc-2.7.so)
==21241==    by 0x804E168: parse_config_data (xl_cmdimpl.c:694)
==21241==    by 0x8056B04: create_domain (xl_cmdimpl.c:1357)
==21241==    by 0x8057ECE: main_create (xl_cmdimpl.c:3154)
==21241==    by 0x804B2FB: main (xl.c:76)