enic: Make dummy rfs functions inline to fix !CONFIG_RFS_ACCEL build

If CONFIG_RFS_ACCEL=n:

drivers/net/ethernet/cisco/enic/enic_main.c: In function 'enic_open':
drivers/net/ethernet/cisco/enic/enic_main.c:1603:2: error: implicit declaration of function 'enic_rfs_flw_tbl_init' [-Werror=implicit-function-declaration]
drivers/net/ethernet/cisco/enic/enic_main.c: In function 'enic_stop':
drivers/net/ethernet/cisco/enic/enic_main.c:1630:2: error: implicit declaration of function 'enic_rfs_flw_tbl_free' [-Werror=implicit-function-declaration]

Introduced in commit a145df23ef32c7b933875f334ba28791ee75766e ("enic: Add
Accelerated RFS support").

Dummy functions are provided, but their prototypes are missing, causing the
build failure. Provide dummy static inline functions instead to fix this.

Signed-off-by: Geert Uytterhoeven <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

drivers/net/ethernet/cisco/enic/enic_clsf.c

···
 	return res;
 }
 
-#else
-
-void enic_rfs_flw_tbl_init(struct enic *enic)
-{
-}
-
-void enic_rfs_flw_tbl_free(struct enic *enic)
-{
-}
-
 #endif /* CONFIG_RFS_ACCEL */

drivers/net/ethernet/cisco/enic/enic_clsf.h

···
 void enic_rfs_flw_tbl_free(struct enic *enic);
 int enic_rx_flow_steer(struct net_device *dev, const struct sk_buff *skb,
 		       u16 rxq_index, u32 flow_id);
+#else
+static inline void enic_rfs_flw_tbl_init(struct enic *enic) {}
+static inline void enic_rfs_flw_tbl_free(struct enic *enic) {}
 #endif /* CONFIG_RFS_ACCEL */
 
 #endif /* _ENIC_CLSF_H_ */