riscv, bpf: use lw when reading int cpu in bpf_get_smp_processor_id

emit_ld is wrong, because thread_info.cpu is 32-bit, not xlen-bit wide.
The struct currently has a hole after cpu, so little endian accesses
seemed fine.

Fixes: 2ddec2c ("riscv, bpf: inline bpf_get_smp_processor_id()")
Cc: stable@vger.kernel.org
Signed-off-by: Radim Krčmář <rkrcmar@ventanamicro.com>
Reviewed-by: Pu Lehui <pulehui@huawei.com>
Link: https://lore.kernel.org/r/20250812090256.757273-4-rkrcmar@ventanamicro.com
Signed-off-by: Paul Walmsley <pjw@kernel.org>

Author: radimkrcmar

arch/riscv/net/bpf_jit_comp64.c

@@ -1763,7 +1763,7 @@ int bpf_jit_emit_insn(const struct bpf_insn *insn, struct rv_jit_context *ctx,
 		 */
 		if (insn->src_reg == 0 && insn->imm == BPF_FUNC_get_smp_processor_id) {
 			/* Load current CPU number in R0 */
-			emit_ld(bpf_to_rv_reg(BPF_REG_0, ctx), offsetof(struct thread_info, cpu),
+			emit_lw(bpf_to_rv_reg(BPF_REG_0, ctx), offsetof(struct thread_info, cpu),
 				RV_REG_TP, ctx);
 			break;
 		}