mwifiex: do not short circuit exit from mwifiex_set_mgmt_ies

Without this change, the code simply exits after calling
mwifiex_uap_set_head_tail_ies, leving the call to
mwifiex_set_mgmt_beacon_data_ies as dead code.

Coverity CID #1271292

Signed-off-by: John W. Linville <linville@tuxdriver.com>
Acked-by: Amitkumar Karwar <akarwar@marvell.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>