hal: Fix NULL pointer dereference in get acdb snd card name

When mixer_get_name returns NULL, acdb snd card name
might be NULL leading to NULL pointer dereference. Fix
this by adding a NULL check for sound card name.

CRs-Fixed: 2390227
Change-Id: I53f83cc8277e1c0e35cb528993b6dd153139be10
1 file changed