ASoC: msm: qdsp6v2: Check for null pointer

Add check for null pointer after kmalloc in
config_debug_fs_init() and log error message if
true.

Signed-off-by: Kenneth Westfield <kwestfie@codeaurora.org>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>