bpf, arm32: fix to use bpf_jit_binary_lock_ro api

Any eBPF JIT that where its underlying arch supports ARCH_HAS_SET_MEMORY
would need to use bpf_jit_binary_{un,}lock_ro() pair instead of the
set_memory_{ro,rw}() pair directly as otherwise changes to the former
might break. arm32's eBPF conversion missed to change it, so fix this
up here.

Fixes: 39c13c204b ("arm: eBPF JIT compiler")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

arch/arm/net/bpf_jit_32.c

@@ -1844,7 +1844,7 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
 		/* there are 2 passes here */
 		bpf_jit_dump(prog->len, image_size, 2, ctx.target);
 
-	set_memory_ro((unsigned long)header, header->pages);
+	bpf_jit_binary_lock_ro(header);
 	prog->bpf_func = (void *)ctx.target;
 	prog->jited = 1;
 	prog->jited_len = image_size;