kbuild: uapi: Drop check_config()

kbuild: uapi: Drop check_config()

headers_install.sh already tests for CONFIG symbols. It does so in a
more comprehensive way, by only checking for references in code and
also running even if CONFIG_UAPI_HEADER_TEST is disabled.
And check_config() has been disabled any case.

Drop the pointless check.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Reviewed-by: Nicolas Schier <nsc@kernel.org>
Link: https://patch.msgid.link/20251230-uapi-check_config-v1-1-00ecec109f39@linutronix.de
Signed-off-by: Nathan Chancellor <nathan@kernel.org>