make install failed for qtlocation module

When I build qt5 I have set configure option --prefix=../../qt5-sdk-android-arm, then the install directory in my machine should be /mnt/sda7/liang/qt/qt5-sdk-android-arm
But the install command in the Makefile generated in /mnt/sda7/liang/qt/qt5/qtlocation/src/positioning/doc/snippets/cpp/ is:

install_target: first FORCE
	@test -d $(INSTALL_ROOT)/libs/armeabi-v7a/ || mkdir -p $(INSTALL_ROOT)/libs/armeabi-v7a/
	-$(INSTALL_PROGRAM) "$(QMAKE_TARGET)" "$(INSTALL_ROOT)/libs/armeabi-v7a/$(QMAKE_TARGET)"

It will try to mkdir in /libs/armeabi-v7a which will failed due to lack of permission. I think it should be $(INSTALL_ROOT)/mnt/sda7/liang/qt/qt5-sdk-android-arm/libs/armeabi-v7a instead