Fixes the following W=1 kernel build warning(s):

 drivers/net/wireless/marvell/mwifiex/pcie.c: In function ‘mwifiex_pcie_remove’:
 drivers/net/wireless/marvell/mwifiex/pcie.c:432:6: warning: variable ‘ret’ set but not used [-Wunused-but-set-variable]
 drivers/net/wireless/marvell/mwifiex/pcie.c: In function ‘mwifiex_cleanup_pcie’:
 drivers/net/wireless/marvell/mwifiex/pcie.c:3142:6: warning: variable ‘ret’ set but not used [-Wunused-but-set-variable]

Cc: Amitkumar Karwar <amitkarwar@gmail.com>
Cc: Ganapathi Bhat <ganapathi.bhat@nxp.com>
Cc: Xinming Hu <huxinming820@gmail.com>
Cc: Kalle Valo <kvalo@codeaurora.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: linux-wireless@vger.kernel.org
Cc: netdev@vger.kernel.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20201102112410.1049272-32-lee.jones@linaro.org