powerpc/bpf ppc32: Do not emit zero extend instruction for 64-bit BPF_END

Suppress emitting zero extend instruction for 64-bit BPF_END_FROM_[L|B]E
operation.

Fixes: 51c66ad849a703 ("powerpc/bpf: Implement extended BPF on PPC32")
Signed-off-by: Naveen N. Rao <[e-mail]>
Reviewed-by: Christophe Leroy <[e-mail]>
Signed-off-by: Michael Ellerman <[e-mail]>
Link: https://lore.kernel.org/r/b4e3[e-mail]

arch/powerpc/net/bpf_jit_comp32.c

···
 			return -EOPNOTSUPP;
 		}
 		if (BPF_CLASS(code) == BPF_ALU && !fp->aux->verifier_zext &&
-		    !insn_is_zext(&insn[i + 1]))
+		    !insn_is_zext(&insn[i + 1]) && !(BPF_OP(code) == BPF_END && imm == 64))
 			EMIT(PPC_RAW_LI(dst_reg_h, 0));
 	}