Fix typo

mic-configure

@@ -145,8 +145,8 @@ distclean: clean
 check:
 	\$(MAKE) -C build_host check
 	\$(MAKE) -C build_mic check ; \
-	RET=$$? ; \
-	STARPU_NCPUS=0 \$(MAKE) -C build_mic check && [ $$RET == 0 ]
+	RET=\$\$? ; \
+	STARPU_NCPUS=0 \$(MAKE) -C build_mic check && [ \$\$RET == 0 ]
 
 showcheck:
 	\$(MAKE) -C build_host showcheck