arm64: bpf: optimize JMP_CALL

Remove superfluous stack frame, saving us 3 instructions for
every JMP_CALL.
Signed-off-by: Zi Shen Lim <zlim.lnx@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

arch/arm64/net/bpf_jit_comp.c

@@ -578,11 +578,8 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx)
 		const u64 func = (u64)__bpf_call_base + imm;
 
 		emit_a64_mov_i64(tmp, func, ctx);
-		emit(A64_PUSH(A64_FP, A64_LR, A64_SP), ctx);
-		emit(A64_MOV(1, A64_FP, A64_SP), ctx);
 		emit(A64_BLR(tmp), ctx);
 		emit(A64_MOV(1, r0, A64_R(0)), ctx);
-		emit(A64_POP(A64_FP, A64_LR, A64_SP), ctx);
 		break;
 	}
 	/* tail call */