bnxt_en: don't consider building bnxt_tc.o if option not enabled

Instead of zeroing out bnxt_tc.c with a #ifdef foo, instead don't compile
the file when the option is not enabled. Now make and the preprocessor do
not have to waste time compiling a no-op.
Signed-off-by: Jonathan Toppins <jtoppins@redhat.com>
Acked-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/broadcom/bnxt/Makefile

 obj-$(CONFIG_BNXT) += bnxt_en.o
 
-bnxt_en-y := bnxt.o bnxt_sriov.o bnxt_ethtool.o bnxt_dcb.o bnxt_ulp.o bnxt_xdp.o bnxt_vfr.o bnxt_tc.o
+bnxt_en-y := bnxt.o bnxt_sriov.o bnxt_ethtool.o bnxt_dcb.o bnxt_ulp.o bnxt_xdp.o bnxt_vfr.o
+bnxt_en-$(CONFIG_BNXT_FLOWER_OFFLOAD) += bnxt_tc.o

drivers/net/ethernet/broadcom/bnxt/bnxt_tc.c

@@ -23,8 +23,6 @@
 #include "bnxt_tc.h"
 #include "bnxt_vfr.h"
 
-#ifdef CONFIG_BNXT_FLOWER_OFFLOAD
-
 #define BNXT_FID_INVALID			0xffff
 #define VLAN_TCI(vid, prio)	((vid) | ((prio) << VLAN_PRIO_SHIFT))
 
@@ -833,6 +831,3 @@ void bnxt_shutdown_tc(struct bnxt *bp)
 	rhashtable_destroy(&tc_info->flow_table);
 	rhashtable_destroy(&tc_info->l2_table);
 }
-
-#else
-#endif