Staging: bcm: Fix double free of 'pReadData' in IOCTL_BCM_NVM_WRITE.

This patch fixes a memory error in ioctl,
IOCTL_BCM_NVM_WRITE. While copying data to
user space, if an error occurs, pReadData
is freed. Then, at the end of the ioctl,
pReadData was being freed again.

Signed-off-by: Kevin McKinney <klmckinney1@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>