isl_output.c: need_exists: drop "bmap" argument
isl_output.c: need_exists: drop "bmap" argument

The "bmap" argument is not actually needed because it is only used
to determine the number of local variables, which can also be obtained
from the list of local variables.
Not taking a "bmap" argument will allow this function to be reused
from isl_printer_print_constraint.

Signed-off-by: Sven Verdoolaege <e5350bbed4977f5eb8ae1dc6abd9ae59d21ace75@kotnet.org>

nicolasvasilache/isl,nicolasvasilache/isl,Meinersbur/isl,inducer/isl-mirror,PollyLabs/isl,PollyLabs/isl,tobig/isl,Meinersbur/isl,inducer/isl-mirror,tobig/isl,inducer/isl-mirror,nicolasvasilache/isl,Meinersbur/isl,Meinersbur/isl,PollyLabs/isl,tobig/isl,inducer/isl-mirror,PollyLabs/isl,PollyLabs/isl,tobig/isl,nicolasvasilache/isl,nicolasvasilache/isl,inducer/isl-mirror