The pseudocode for this operation is an increment + compare loop,
so comparing <= the maximum integer produces an all-true predicate.

Rather than bound in both the inline code and the helper, pass the
helper the number of predicate bits to set instead of the number
of predicate elements to set.
Reported-by: NLaurent Desnogues <laurent.desnogues@gmail.com>
Signed-off-by: NRichard Henderson <richard.henderson@linaro.org>
Reviewed-by: NLaurent Desnogues <laurent.desnogues@gmail.com>
Tested-by: NAlex Bennée <alex.bennee@linaro.org>
Tested-by: NLaurent Desnogues <laurent.desnogues@gmail.com>
Message-id: 20180801123111.3595-4-richard.henderson@linaro.org
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>