net: cxgb3: remove unused fl_to_qset function

clang with W=1 reports
drivers/net/ethernet/chelsio/cxgb3/sge.c:169:32: error: unused function
  'fl_to_qset' [-Werror,-Wunused-function]
static inline struct sge_qset *fl_to_qset(const struct sge_fl *q, int qidx)
                               ^
This function is not used, so remove it.

Signed-off-by: Tom Rix <trix@redhat.com>
Reviewed-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Link: https://lore.kernel.org/r/20230319172433.1708161-1-trix@redhat.com


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