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

* gnu/packages/bash.scm
  (bash)[arguments]<#:configure-flags>: Use this-package-input
  instead of %build-inputs.
---
 gnu/packages/bash.scm | 35 +++++++++++++++++++----------------
 1 file changed, 19 insertions(+), 16 deletions(-)