tools/bpf: bpftool, add xskmap in map types

When listed all maps, bpftool currently shows (null) for xskmap.
Added xskmap type in map_type_name[] to show correct type.

Signed-off-by: Prashant Bhole <bhole_prashant_q7@lab.ntt.co.jp>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

tools/bpf/bpftool/map.c

@@ -68,6 +68,7 @@ static const char * const map_type_name[] = {
 	[BPF_MAP_TYPE_DEVMAP]		= "devmap",
 	[BPF_MAP_TYPE_SOCKMAP]		= "sockmap",
 	[BPF_MAP_TYPE_CPUMAP]		= "cpumap",
+	[BPF_MAP_TYPE_XSKMAP]           = "xskmap",
 	[BPF_MAP_TYPE_SOCKHASH]		= "sockhash",
 	[BPF_MAP_TYPE_CGROUP_STORAGE]	= "cgroup_storage",
 };