i40e: Remove unused i40e_get_cur_guaranteed_fd_count

The last use of i40e_get_cur_guaranteed_fd_count() was removed in 2015 by
commit 04294e38 ("i40e: FD filters flush policy changes")

Remove it.

Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Reviewed-by: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>
Reviewed-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Link: https://patch.msgid.link/20250102173717.200359-6-linux@treblig.org


Signed-off-by: Jakub Kicinski <kuba@kernel.org>