scripts: headers_install.sh: Update config leak ignore entries

Remove two dated config leak ignore entries from scripts/headers_install.sh:
arch/alpha/include/uapi/asm/setup.h does no more leak any CONFIG_* symbol to
user-space any more since commit 3cb8b153 ("alpha: Move setup.h out of
uapi").
Same holds for include/uapi/asm-generic/fcntl.h since commit 306f7cc1
("uapi: always define F_GETLK64/F_SETLK64/F_SETLKW64 in fcntl.h").

Signed-off-by: Nicolas Schier <nicolas@fjasle.eu>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>