target/arm: Return correct IL bit in merge_syn_data_abort

target/arm: Return correct IL bit in merge_syn_data_abort

The IL bit is set for 32-bit instructions, thus passing false
with the is_16bit parameter to syn_data_abort_with_iss() makes
a syn mask that always has the IL bit set.

Pass is_16bit as true to make the initial syn mask have IL=0,
so that the final IL value comes from or'ing template_syn.

Cc: [email protected]
Fixes: aaa1f954d4ca ("target-arm: A64: Create Instruction Syndromes for Data Aborts")
Signed-off-by: Jeff Kubascik <[email protected]>
Signed-off-by: Richard Henderson <[email protected]>
Message-id: 20200117004618[email protected]
[rth: Extracted this as a self-contained bug fix from a larger patch]
Signed-off-by: Richard Henderson <[email protected]>
Reviewed-by: Peter Maydell <[email protected]>
Signed-off-by: Peter Maydell <[email protected]>