bug#44330: 26.3; doc string of `cl-some'

[Drew Adams]

"Return true if PREDICATE is true of any element of SEQ or SEQs.
If so, return the true (non-nil) value returned by PREDICATE."
                                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^

The second sentence is meaningless/underspecified.  If the function
stops as soon as it finds the first element for which PREDICATE is
true then the doc should say that it returns the value returned by
PREDICATE _for that element_.

Without specifying, in some way, for which element the application of
PREDICATE returns non-nil, "the value returned by PREDICATE" has no
meaning.

In GNU Emacs 26.3 (build 1, x86_64-w64-mingw32)
 of 2019-08-29
Repository revision: 96dd0196c28bc36779584e47fffcca433c9309cd
Windowing system distributor `Microsoft Corp.', version 10.0.18362
Configured using:
 `configure --without-dbus --host=x86_64-w64-mingw32
 --without-compress-install 'CFLAGS=-O2 -static -g3''