iw_cxgb4: Remove __func__ parameter from pr_debug()

pr_debug() can be enabled to print function names, So removing the
unwanted __func__ parameters from debug logs.
Realign function parameters.

Signed-off-by: Potnuri Bharat Teja <bharat@chelsio.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>