msm: npu: Prevent network from being used after free

Function wait_for_completion_interruptible_timeout will return after
receiving a signal which would cause the network data structure to be
used after it is freed. This change is to handle this scenario properly
to avoid use-after-free issue.

Change-Id: Icb74b3e7a5cb6c3201738c1952948d308333993e
Signed-off-by: Jilai Wang <jilaiw@codeaurora.org>