print/py-uharfbuzz: Remove -f because RM has it already

print/py-uharfbuzz/Makefile

@@ -19,7 +19,7 @@ USES=		compiler:c++11-lang python:3.6+ zip
 USE_PYTHON=	autoplist concurrent cython distutils
 
 post-patch:
-	@${RM} -fr ${WRKSRC}/harfbuzz/
+	@${RM} -r ${WRKSRC}/harfbuzz/
 	@${REINPLACE_CMD} -e 's|%%LOCALBASE%%|${LOCALBASE}|' ${WRKSRC}/setup.py ${WRKSRC}/src/uharfbuzz/_harfbuzz.cpp
 
 .include <bsd.port.mk>