busybox

ash: Set SHLVL in ASH_BASH_COMPAT

function                                             old     new   delta
ash_main                                            1456    1505     +49
.rodata                                           148488  148494      +6
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(add/remove: 0/0 grow/shrink: 2/0 up/down: 55/0)               Total: 55 bytes

Signed-off-by: Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>