realtek/rtl838x: regression in f909059b74 caused by procd segfault in libubox

[Dustin Howett]

I am seeing this on x86/64-glibc as well.

It looks like procd is falling over in udebug_entry_vprintf at the
*second* vprintf after udebug_buf_alloc.
This appears to occur when there are log messages longer than the
minimum allocation size (128) and we trip into the second allocation
pass.

Stack:
/lib/libc.so.6(+0xa3af6)[0x7fe807b8baf6]
/lib/libc.so.6(+0x5a6f1)[0x7fe807b426f1]
/lib/libc.so.6(_vsnprintf+0x4e)[0x7fe807b6110e]
/lib/libubox.so.202312041(udebug_entry_vprintf+0xa8)[0x7fe807d19e6c]
/lib/libubox.so.202312041(ulog+0xc0)[0x7fe807d18bed]
/sbin/procd.real(+0xacc4) [0x557134c1dcc4]
/lib/libubox.so.202312041(+0x74e2)[0x7fe807d174e2]
/lib/libubox.so.202312041(uloop_run_timeout+0x243)[0x7fe807d161d8]
/sbin/procd.real(main+0x14b)[0x557134c1b193]
/lib/libc.so.6(+0x27577)[0x7fe807b0f577]
/lib/libc.so.6(_libc_start_main+0x86)[0x7fe807b0f636]
/sbin/procd.real(_start+0x21)[0x557134c1b1d1]

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