qga: fitering out -fstack-protector-strong

configure script may add -fstack-protector-strong option instead
of -fstack-protector-all, depending on availability ( see
commit 63678e17 ). Both options have to by filtered out for
qga-vss.dll, otherwise MinGW cross-compilation fails at linking
stage.
Signed-off-by: NJoseph Hindin <jhindin@daynix.com>
Message-Id: <1427906337-20805-2-git-send-email-jhindin@daynix.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

qga/vss-win32/Makefile.objs

@@ -3,7 +3,7 @@
 qga-vss-dll-obj-y += requester.o provider.o install.o
 
 obj-qga-vss-dll-obj-y = $(addprefix $(obj)/, $(qga-vss-dll-obj-y))
-$(obj-qga-vss-dll-obj-y): QEMU_CXXFLAGS = $(filter-out -Wstrict-prototypes -Wmissing-prototypes -Wnested-externs -Wold-style-declaration -Wold-style-definition -Wredundant-decls -fstack-protector-all, $(QEMU_CFLAGS)) -Wno-unknown-pragmas -Wno-delete-non-virtual-dtor
+$(obj-qga-vss-dll-obj-y): QEMU_CXXFLAGS = $(filter-out -Wstrict-prototypes -Wmissing-prototypes -Wnested-externs -Wold-style-declaration -Wold-style-definition -Wredundant-decls -fstack-protector-all -fstack-protector-strong, $(QEMU_CFLAGS)) -Wno-unknown-pragmas -Wno-delete-non-virtual-dtor
 
 $(obj)/qga-vss.dll: LDFLAGS = -shared -Wl,--add-stdcall-alias,--enable-stdcall-fixup -lole32 -loleaut32 -lshlwapi -luuid -static
 $(obj)/qga-vss.dll: $(obj-qga-vss-dll-obj-y) $(SRC_PATH)/$(obj)/qga-vss.def