ALSA: usb-audio: Change structure initialisation to C99 style

To allow for structure randomisation, replace the in order struct
initialisation style with explicit field style.

The Coccinelle semantic patch used to make this change is as follows:

@decl@
identifier i1,fld;
type T;
field list[n] fs;
@@

struct i1 {
 fs
 T fld;
 ...};

@@
identifier decl.i1,i2,decl.fld;
expression e;
position bad.p, bad.fix;
@@

struct i1 i2@p = { ...,
+ .fld = e
- e@fix
 ,...};

Signed-off-by: Amitoj Kaur Chawla <amitoj1606@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>