bug#12888: 24.3.50; (minor) grammar fix for (elisp) `Syntactic Font Lock'

[Drew Adams]

> > Correct this sentence, which is not grammatical:
> >  
> >  If the value of this variable is non-`nil', Font Lock does not do
> >  syntactic fontification, only search-based fontification based on
> >  `font-lock-keywords'.
> 
> The sentence is grammatical.

No, sorry; it is not.  Here is one possible fix, in case you are interested in
improvement and can get beyond being defensive:

If the value of this variable is non-`nil', Font Lock does not do
syntactic fontification; it does only search-based fontification based on
`font-lock-keywords'.

But as the subject line suggests, grammar here is a minor consideration.  The
meaning is clear enough, even if the grammar is not correct.  Not a big deal.
HTH.