bpf: make bpf_prog_offload_verifier_prep() static inline

Header implementation of bpf_prog_offload_verifier_prep() which
is used if CONFIG_NET=n should be a static inline.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

include/linux/bpf_verifier.h

@@ -171,7 +171,7 @@ static inline struct bpf_reg_state *cur_regs(struct bpf_verifier_env *env)
 #if defined(CONFIG_NET) && defined(CONFIG_BPF_SYSCALL)
 int bpf_prog_offload_verifier_prep(struct bpf_verifier_env *env);
 #else
-int bpf_prog_offload_verifier_prep(struct bpf_verifier_env *env)
+static inline int bpf_prog_offload_verifier_prep(struct bpf_verifier_env *env)
 {
 	return -EOPNOTSUPP;
 }