Avoid to call 'make' explicitely, because on non-linux system it would call wrong make

Author: vbwagner

contrib/postgres_fdw/Makefile

@@ -29,5 +29,5 @@ endif
 # Poor's man overload of already defined target: just copy it
 check: submake $(REGRESS_PREP)
 	$(pg_regress_check) $(REGRESS_OPTS) $(REGRESS)
-	env DESTDIR='$(abs_top_builddir)'/tmp_install make install
+	env DESTDIR='$(abs_top_builddir)'/tmp_install $(MAKE) install
 	$(prove_check)