makepkg: refactor checking for write permissions into a utility function

Additionally provide a separate error for failure to create the
directory vs lack of write permissions on a pre-existing directory.

This also means we now consistently try to create any nonexistent *DEST
directories as needed before aborting with E_FS_PERMISSIONS. Previously
only $BUILDDIR received that kindness.

Fixes FS#43537

Signed-off-by: Eli Schwartz <eschwartz@archlinux.org>
Signed-off-by: Allan McRae <allan@archlinux.org>

0 files changed, 0 insertions, 0 deletions