qcacld-3.0: Refactor WE_SET_VHT_RATE processing

One of the HDD functions with the highest cyclomatic complexity is
__iw_setint_getnone(). The handing of WE_SET_VHT_RATE has a complexity
greater than 1, so refactor that logic into a separate function to
help reduce the complexity of __iw_setint_getnone().

Change-Id: I07299bcc7e1cba7b5ceced3ba1cf22c470cb448e
CRs-Fixed: 2340146
1 file changed