This patch replaces static variable from send_cmd_sync
with flag in priv->status. It was used for reentrance protection
but clearly made it impossible to stuck more cards into the same machine

In addition it force check of return values of synchronous commands
commands that doesn't requires return value async commands have to be used
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NYi Zhu <yi.zhu@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This patch provides a default callback for ASYNC host commands instead
of calling to BUG_ON. Most of the callbacks are now just empty functions
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

1. Host command sending functions moved from iwl4965-base.c to iwl-hcmd.c
in iwlcore module
2. enqueue_hcmd function currently stays in iwl4965-base.c. It is invoked
   through the new 'utils' field in priv's ops.
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NAssaf Krauss <assaf.krauss@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>