qcacld-3.0: Refactor WE_SET_AMSDU processing

One of the HDD functions with the highest cyclomatic complexity is
__iw_setint_getnone(). The handing of WE_SET_AMSDU 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: I74bbc055c1587fff548512f4c7f325f75345eb95
CRs-Fixed: 2340147
1 file changed