bpf: fix UML x86_64 compile failure

pcpu_hot (defined in arch/x86) is not available on user mode linux (ARCH=um)

Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Fixes: 1ae69210 ("bpf: inline bpf_get_smp_processor_id() helper")
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Link: https://lore.kernel.org/r/20240613173146.2524647-1-maze@google.comSigned-off-by: Alexei Starovoitov <ast@kernel.org>

kernel/bpf/verifier.c

@@ -20320,7 +20320,7 @@ static int do_misc_fixups(struct bpf_verifier_env *env)
 			goto next_insn;
 		}
 
-#ifdef CONFIG_X86_64
+#if defined(CONFIG_X86_64) && !defined(CONFIG_UML)
 		/* Implement bpf_get_smp_processor_id() inline. */
 		if (insn->imm == BPF_FUNC_get_smp_processor_id &&
 		    prog->jit_requested && bpf_jit_supports_percpu_insn()) {