Fix comma in $(if ...).

Change-Id: I2f9fba5b5c0384ef12ee9e5f48fa01102436a425
diff --git a/core/definitions.mk b/core/definitions.mk
index 0278150..3d9a73a 100644
--- a/core/definitions.mk
+++ b/core/definitions.mk
@@ -1329,7 +1329,7 @@
 $(hide) $(PRIVATE_CXX) \
 	-nostdlib -Wl,-soname,$(notdir $@) \
 	-Wl,--gc-sections \
-	$(if $(filter true,$(PRIVATE_CLANG)),-shared,-Wl,-shared) \
+	$(if $(filter true,$(PRIVATE_CLANG)),-shared,-Wl$(comma)-shared) \
 	$(PRIVATE_TARGET_GLOBAL_LD_DIRS) \
 	$(if $(filter true,$(PRIVATE_NO_CRT)),,$(PRIVATE_TARGET_CRTBEGIN_SO_O)) \
 	$(PRIVATE_ALL_OBJECTS) \