scripts: get_abi.pl: fix fallback rule for undefined symbols

scripts: get_abi.pl: fix fallback rule for undefined symbols

The rule that falls back to the long regex list is wrong:
it is just running again the same loop it did before.

change it to look at the "others" table.

That slows the processing speed, but provides a better
list of undefined symbols.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/a3ba919e9a9208a5f012a13c9674c362a9d73169.1632994565.git.mchehab+huawei@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>