iwlwifi: fix possible data overwrite in hcmd callback

iwlwifi: fix possible data overwrite in hcmd callback

My commit 3598e1774c94e55c71b585340e7dc4538f310e3f
"iwlwifi: fix enqueue hcmd race conditions" move hcmd callback after
command queue reclaim, to avoid call it with hcmd_lock. But since
queue read index was updated, cmd data can be overwritten. Fix problem
by calling callback before taking hcmd_lock and queue reclaim.

Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Acked-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>