%build-inputs does not exist when cross-compiling,
so use #$(this-package-input ...) instead.

* gnu/packages/fontutils.scm
  (fontconfig)[arguments]<#:configure-flags>: Use this-package-input
  instead of %build-inputs.
---
 gnu/packages/fontutils.scm | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)