llvm5.0: use input kind helper to avoid breakage
llvm5.0: use input kind helper to avoid breakage

Upstream llvm renamed an enum, so use a helper function that is
available in all versions to fix compatibility.

Signed-off-by: Brenden Blanco <8e41c261aa8ddb01230a40c21c26a049c1f6d041@gmail.com>

tuxology/bcc,romain-intel/bcc,tuxology/bcc,iovisor/bcc,romain-intel/bcc,romain-intel/bcc,mcaleavya/bcc,iovisor/bcc,iovisor/bcc,brendangregg/bcc,iovisor/bcc,mcaleavya/bcc,brendangregg/bcc,iovisor/bcc,romain-intel/bcc,tuxology/bcc,brendangregg/bcc,brendangregg/bcc,romain-intel/bcc,mcaleavya/bcc,mcaleavya/bcc,tuxology/bcc,brendangregg/bcc,mcaleavya/bcc,tuxology/bcc