Rework sysroot option handling

The external toolchain and internal toolchain cases both need to use
the --sysroot option, and they have almost identical
LDFLAGS/CFLAGS/CXXFLAGS definition, so we can factorize these
definitions.

Moreover, the --isysroot option is implied by --sysroot so there's no
need to specify both.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/Makefile.in

@@ -77,23 +77,13 @@ ifeq ($(BR2_LARGEFILE),y)
 TARGET_CFLAGS+=-D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64
 endif
 
-
-#########################################################################
 ifeq ($(BR2_TOOLCHAIN_BUILDROOT),y)
 TARGET_CFLAGS+=-I$(STAGING_DIR)/usr/include -I$(STAGING_DIR)/include
-TARGET_LDFLAGS+=-L$(STAGING_DIR)/lib -L$(STAGING_DIR)/usr/lib
-TARGET_CXXFLAGS=$(TARGET_CFLAGS)
-TARGET_CFLAGS+= $(BR2_SYSROOT) $(BR2_ISYSROOT)
-TARGET_LDFLAGS+= $(BR2_SYSROOT)
+endif
 
-#########################################################################
-else ifeq ($(BR2_TOOLCHAIN_EXTERNAL),y)
-TARGET_CFLAGS+=--sysroot=$(STAGING_DIR)/
+TARGET_LDFLAGS+=-L$(STAGING_DIR)/lib -L$(STAGING_DIR)/usr/lib --sysroot=$(STAGING_DIR)
+TARGET_CFLAGS+=--sysroot=$(STAGING_DIR)
 TARGET_CXXFLAGS=$(TARGET_CFLAGS)
-TARGET_LDFLAGS=--sysroot=$(STAGING_DIR)/
-TARGET_LDFLAGS+=-L$(STAGING_DIR)/lib -L$(STAGING_DIR)/usr/lib
-endif
-#########################################################################
 
 # Compute GNU_TARGET_NAME and REAL_GNU_TARGET_NAME
 GNU_TARGET_NAME=$(ARCH)-linux

toolchain/Makefile.in

@@ -15,8 +15,6 @@ BR2_SYSROOT_TARGET_DESTDIR=DESTDIR=$(TARGET_DIR)/
 BR2_CONFIGURE_DEVEL_SYSROOT=--with-sysroot=$(TOOLCHAIN_DIR)/uClibc_dev/
 BR2_CONFIGURE_STAGING_SYSROOT=--with-sysroot=$(STAGING_DIR)
 BR2_CONFIGURE_BUILD_TOOLS=--with-build-time-tools=$(STAGING_DIR)/usr/$(REAL_GNU_TARGET_NAME)/bin
-BR2_SYSROOT=--sysroot=$(STAGING_DIR)/
-BR2_ISYSROOT=-isysroot $(STAGING_DIR)
 
 # gcc has a bunch of needed stuff....
 include toolchain/gcc/Makefile.in