iwmc3200wifi: Handle UMAC stalls and UMAC assert properly

When UMAC stalls or asserts, we want to reset the device. But when we're
associated, the current reset worker will end up calling
cfg80211_connect_result() with the cfg80211 sme layer knowing that we're
reassociating. That ends up with some ugly warnings.
With this patch we're telling the upper layer that we've roamed if
reassociation succeeds, and that we're disconnected if it fails.

Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>