Makefile: fix typo
seems typo
@@ -5,8 +5,8 @@ HOSTOS := $(shell uname -s)
GPIOSUPPORT=off
CC = gcc
-+CFLAGS ?= -O3 -Wall -Wextra
-+CFLAGS += -std=gnu99
+CFLAGS ?= -O3 -Wall -Wextra
+CFLAGS += -std=gnu99
INSTFLAGS = -m 0755
ifeq ($(HOSTOS), Linux)
