netlink: smaller nla_attr_minlen table

Length of a netlink attribute may be u16 but lengths of basic attributes
are much smaller, so small we can save 16 bytes of .rodata and pocket
change inside .text.

16-bit is worse on x86-64 than 8-bit because of operand size override prefix.

	add/remove: 0/0 grow/shrink: 0/3 up/down: 0/-19 (-19)
	function                                     old     new   delta
	validate_nla                                 418     417      -1
	nla_policy_len                                66      64      -2
	nla_attr_minlen                               32      16     -16
	Total: Before=154865051, After=154865032, chg -0.00%

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

lib/nlattr.c

@@ -14,7 +14,7 @@
 #include <linux/types.h>
 #include <net/netlink.h>
 
-static const u16 nla_attr_minlen[NLA_TYPE_MAX+1] = {
+static const u8 nla_attr_minlen[NLA_TYPE_MAX+1] = {
 	[NLA_U8]	= sizeof(u8),
 	[NLA_U16]	= sizeof(u16),
 	[NLA_U32]	= sizeof(u32),