cfg.mk: check ctype_macros only on *.[c|h] files
cfg.mk: check ctype_macros only on *.[c|h] files

The functions like isalnum(), isalpha(), isdigit(), etc. are also
available in Python, however `make syntax-check` do not intend to
prohibit them.

Reviewed-by: Daniel P. Berrangé <bb938cf255e055ff3507f2627d214e8e62118fcf@redhat.com>
Signed-off-by: Radostin Stoyanov <31e0ffafc95759db9487554f968b40977ab67b6b@gmail.com>

nertpinx/libvirt,olafhering/libvirt,andreabolognani/libvirt,nertpinx/libvirt,olafhering/libvirt,nertpinx/libvirt,crobinso/libvirt,eskultety/libvirt,jardasgit/libvirt,fabianfreyer/libvirt,jardasgit/libvirt,nertpinx/libvirt,libvirt/libvirt,zippy2/libvirt,libvirt/libvirt,crobinso/libvirt,crobinso/libvirt,fabianfreyer/libvirt,jardasgit/libvirt,libvirt/libvirt,eskultety/libvirt,andreabolognani/libvirt,eskultety/libvirt,eskultety/libvirt,olafhering/libvirt,fabianfreyer/libvirt,olafhering/libvirt,zippy2/libvirt,zippy2/libvirt,zippy2/libvirt,jardasgit/libvirt,libvirt/libvirt,fabianfreyer/libvirt,andreabolognani/libvirt,nertpinx/libvirt,andreabolognani/libvirt,eskultety/libvirt,jfehlig/libvirt,jfehlig/libvirt,jardasgit/libvirt,crobinso/libvirt,fabianfreyer/libvirt,jfehlig/libvirt,jfehlig/libvirt,andreabolognani/libvirt