bpf: btf: Remove two unused function declarations

Commit db559117 ("bpf: Consolidate spin_lock, timer management into btf_record")
removed the implementations but leave declarations.
Signed-off-by: Yue Haibing <yuehaibing@huawei.com>
Link: https://lore.kernel.org/r/20230808145741.33292-1-yuehaibing@huawei.comSigned-off-by: Martin KaFai Lau <martin.lau@kernel.org>

include/linux/btf.h

@@ -204,8 +204,6 @@ u32 btf_nr_types(const struct btf *btf);
 bool btf_member_is_reg_int(const struct btf *btf, const struct btf_type *s,
 			   const struct btf_member *m,
 			   u32 expected_offset, u32 expected_size);
-int btf_find_spin_lock(const struct btf *btf, const struct btf_type *t);
-int btf_find_timer(const struct btf *btf, const struct btf_type *t);
 struct btf_record *btf_parse_fields(const struct btf *btf, const struct btf_type *t,
 				    u32 field_mask, u32 value_size);
 int btf_check_and_fixup_fields(const struct btf *btf, struct btf_record *rec);