manibuilder/anita: Export library path for libusb

This allows to actually run the built flashprog binary.

Change-Id: If09c0da7c1c19c7fc948ba6e2b7537e0ff017d97
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.sourcearcade.org/c/flashprog/+/133
diff --git a/util/manibuilder/Makefile b/util/manibuilder/Makefile
index e325357..fe5cdcf 100644
--- a/util/manibuilder/Makefile
+++ b/util/manibuilder/Makefile
@@ -62,6 +62,7 @@
 		--name mani_$(call ident,$*) mani/$* \
 		"git fetch $(TEST_REMOTE) $(TEST_REVISION) && \
 		 git checkout FETCH_HEAD && \
+		 export $(ENV_VARS) && \
 		 $(MAKECMD) clean && $(MAKECMD) -j$${CPUS:-1} CC='$(CC)' \
 		 $(if $(STRIP),STRIP='$(STRIP)') \
 		 $(if $(LIBS_BASE),LIBS_BASE='$(LIBS_BASE)') \