Bug 1083572 - Apply some make black magic to make the fix actually work

config/external/nss/Makefile.in

@@ -244,7 +244,8 @@ DEFAULT_GMAKE_FLAGS += XCFLAGS='$(CFLAGS)'
 DEFAULT_GMAKE_FLAGS += DARWIN_DYLIB_VERSIONS='-compatibility_version 1 -current_version 1 $(LDFLAGS)'
 endif
 ifeq (1_1,$(CLANG_CL)_$(MOZ_ASAN))
-DEFAULT_GMAKE_FLAGS += XLDFLAGS='$(OS_LDFLAGS)'
+XLDFLAGS := $(OS_LDFLAGS)
+DEFAULT_GMAKE_FLAGS += XLDFLAGS='$(XLDFLAGS)'
 endif
 
 DEFAULT_GMAKE_FLAGS += NSS_NO_PKCS11_BYPASS=1