msm: cpp: Add missing error handling checks

Ensure that mutex is unlocked after updating fw_name_bin
value.
Free the command message and frame info if there is a copy
to user error.
Check for validity of length of ioctl pointer.

Change-Id: Ife3f86dc450c496a11517f49727211ba92c0b2e3
Signed-off-by: Krishnankutty Kolathappilly <kkolatha@codeaurora.org>