Removing conflicting compilation flags from the Makefile

Signed-off-by: Serge Ayoun <serge.ayoun@intel.com>

Makefile

@@ -12,7 +12,7 @@ KDIR := /lib/modules/$(shell uname -r)/build
 PWD  := $(shell pwd)
 
 default:
-	$(MAKE) -C $(KDIR) SUBDIRS=$(PWD) CFLAGS_MODULE="-DDEBUG -g -O0" modules
+	$(MAKE) -C $(KDIR) SUBDIRS=$(PWD) modules
 
 install: default
 	$(MAKE) INSTALL_MOD_DIR=kernel/drivers/intel/sgx -C $(KDIR) M=$(PWD) modules_install