tools/syz-kconf: warn about the leading CONFIG_ in .yml files
tools/syz-kconf: warn about the leading CONFIG_ in .yml files

Config option names in .yml files should be specified without the
CONFIG_ prefix (similarly to how they are written in .config files).

Accidentally writing the CONFIG_ prefix leads to non-obvious bugs that
are hard to spot.

Make kconf print a warning about config options with the leading
CONFIG_, e.g.:

  Warning: excessive CONFIG_ in CONFIG_IPC_NS at base.yml:76 ?

xairy/syzkaller,google/syzkaller,google/syzkaller,google/syzkaller,xairy/syzkaller,google/syzkaller,google/syzkaller,xairy/syzkaller,xairy/syzkaller,xairy/syzkaller,google/syzkaller,xairy/syzkaller,xairy/syzkaller,google/syzkaller