ARC: bpf: Correct conditional check in 'check_jmp_32'

The original code checks 'if (ARC_CC_AL)', which is always true since
ARC_CC_AL is a constant. This makes the check redundant and likely
obscures the intention of verifying whether the jump is conditional.

Updates the code to check cond == ARC_CC_AL instead, reflecting the intent
to differentiate conditional from unconditional jumps.

Suggested-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
Reviewed-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
Acked-by: Shahab Vahedi <list+bpf@vahedi.org>
Signed-off-by: Hardevsinh Palaniya <hardevsinh.palaniya@siliconsignals.io>
Signed-off-by: Vineet Gupta <vgupta@kernel.org>