mwifiex: fix system crash observed during initialisation

System crash was observed if one of the driver initialisation
commands is timed out. The reason is our timeout handler triggers
firmware dump, meanwhile driver initialisation error paths have
already freed the adapter structure.

Firmware hasn't yet completely initialized. So collecting firmware
dump is not needed in this case. Command timeout handler is
modified in this patch to fix the crash issue.

Signed-off-by: Zhaoyang Liu <liuzy@marvell.com>
Signed-off-by: Amitkumar Karwar <akarwar@marvell.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>