msm-core: Unregister uio device on failed probe

In certain error scenarios, the probe function returns error code without
actually freesing the uio device. This could result in a panic when
userspace accesses the uio device.

Fix by freeing the uio device on faileed probe.

Change-Id: I20af803a10407206759d3aeeac5bf59f674b3d04
Signed-off-by: Mahesh Sivasubramanian <msivasub@codeaurora.org>