docs: kbuild: fix typo

on -> one.
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Documentation/kbuild/kconfig-language.rst

@@ -672,7 +672,7 @@ Future kconfig work
 Work on kconfig is welcomed on both areas of clarifying semantics and on
 evaluating the use of a full SAT solver for it. A full SAT solver can be
 desirable to enable more complex dependency mappings and / or queries,
-for instance on possible use case for a SAT solver could be that of handling
+for instance one possible use case for a SAT solver could be that of handling
 the current known recursive dependency issues. It is not known if this would
 address such issues but such evaluation is desirable. If support for a full SAT
 solver proves too complex or that it cannot address recursive dependency issues