common/do_check: move make_check_pre behind env setting

All environment variables setting in command execution must be put
before any non-variables-like, otherwise, they're intepretted as
something else.

Fix: 71b11fdbdb, (xbps-src: add make_check_pre, 2022-02-28)

common/build-style/raku-dist.sh

@@ -3,7 +3,7 @@
 #
 
 do_check() {
-	${make_check_pre} RAKULIB=lib prove -r -e raku t/
+	RAKULIB=lib ${make_check_pre} prove -r -e raku t/
 }
 
 do_install() {