libmach: use the standardized format for designated initializers.

The brace style in these files are a little inconsistent so I rolled with
it on a per-file basis.

R=dave, r
CC=golang-dev
https://golang.org/cl/4515194

src/libmach/obj.c

@@ -81,17 +81,17 @@ struct	Obj		/* functions to handle each intermediate (.$O) file */
 
 static Obj	obj[] =
 {			/* functions to identify and parse each type of obj */
-	[Obj68020]	"68020 .2",	_is2, _read2,
-	[ObjAmd64]	"amd64 .6",	_is6, _read6,
-	[ObjArm]	"arm .5",	_is5, _read5,
-	[ObjAlpha]	"alpha .7",	_is7, _read7,
-	[Obj386]	"386 .8",	_is8, _read8,
-	[ObjSparc]	"sparc .k",	_isk, _readk,
-	[ObjPower]	"power .q",	_isq, _readq,
-	[ObjMips]	"mips .v",	_isv, _readv,
-	[ObjSparc64]	"sparc64 .u",	_isu, _readu,
-	[ObjPower64]	"power64 .9",	_is9, _read9,
-	[Maxobjtype]	0, 0
+	[Obj68020]   = { "68020 .2",	_is2, _read2 },
+	[ObjAmd64]   = { "amd64 .6",	_is6 , _read6 },
+	[ObjArm]     = { "arm .5",	_is5, _read5 },
+	[ObjAlpha]   = { "alpha .7",	_is7, _read7 },
+	[Obj386]     = { "386 .8",	_is8, _read8 },
+	[ObjSparc]   = { "sparc .k",	_isk, _readk },
+	[ObjPower]   = { "power .q",	_isq, _readq },
+	[ObjMips]    = { "mips .v",	_isv, _readv },
+	[ObjSparc64] = { "sparc64 .u",  _isu, _readu },
+	[ObjPower64] = { "power64 .9",	_is9, _read9 },
+	[Maxobjtype] = { 0, 0, 0 }
 };
 
 struct	Symtab