qcacld-3.0: Relocate hdd_set_tx_stbc() mac_handle test

hdd_set_tx_stbc() is called from both the STA and SAP ioctl
handlers. In the STA case the caller checks the mac_handle, but in the
SAP case the mac_handle is not checked. This could result in a bad
mac_handle being used in the SAP case. In order to cover both cases
relocate the mac_handle test to hdd_set_tx_stbc().

Note that this has the added benefit of reducing the cyclomatic
complexity of __iw_setint_getnone(), one of the HDD functions with the
highest complexity.

Change-Id: Ie7a01ddbfb958ab87b7baf11e93d8a86c32744b7
CRs-Fixed: 2339227
2 files changed