makepkg: do not chmod $BUILDDIR itself after checking for its existence

In commit d8717a6a

 the write permission
checks were refactored. Initially we intended to drop this chmod in the
process, but due to some confusion about whether it was needed, I ended
up submitting patches both to preserve and to remove it... but it's not
needed after all. We do it on the individual $srcdir/$pkgdir, later on.

Then, we used the wrong version, which causes unnecessary restrictions.

See FS#58790
Signed-off-by: Eli Schwartz <eschwartz@archlinux.org>
Signed-off-by: Allan McRae <allan@archlinux.org>

scripts/makepkg.sh.in

@@ -1371,7 +1371,6 @@ if ! ensure_writable_dir "BUILDDIR" "$BUILDDIR"; then
 	plain "$(gettext "Aborting...")"
 	exit $E_FS_PERMISSIONS
 fi
-chmod a-s "$BUILDDIR"
 
 if (( ! (NOBUILD || GENINTEG) )) && ! ensure_writable_dir "PKGDEST" "$PKGDEST"; then
 	plain "$(gettext "Aborting...")"