iwlwifi: pcie: free RBs during configure

iwlwifi: pcie: free RBs during configure

When switching op-modes, or more generally when reconfiguring,
we might switch the RB size. In _iwl_pcie_rx_init() we have a
comment saying we must free all RBs since we might switch the
size, but this is actually too late: the switch has been done
and we'll free the buffers with the wrong size.

Fix this by always freeing the buffers, if any, at the start
of configure, instead of only after the size may have changed.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20210802170640.42d7c93279c4.I07f74e65aab0e3d965a81206fcb289dc92d74878@changeid
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>