[fix] decoupling librocksdb.a

Author: warrick1016

src/Makefile

@@ -445,7 +445,6 @@ persist-settings:
 .make-compile-prerequisites:
 	@if [ ! -f $@ ]; then \
 		echo "Building compile dependencies for first time..."; \
-		touch $@; \
 		echo STD=$(STD) > .make-settings; \
 		echo WARN=$(WARN) >> .make-settings; \
 		echo OPT=$(OPT) >> .make-settings; \
@@ -458,7 +457,8 @@ persist-settings:
 		echo REDIS_LDFLAGS=$(REDIS_LDFLAGS) >> .make-settings; \
 		echo PREV_FINAL_CFLAGS=$(FINAL_CFLAGS) >> .make-settings; \
 		echo PREV_FINAL_LDFLAGS=$(FINAL_LDFLAGS) >> .make-settings; \
-		(cd ../deps && $(MAKE) $(DEPENDENCY_TARGETS) > /dev/null 2>&1); \
+		cd ../deps && $(MAKE) $(DEPENDENCY_TARGETS); \
+		touch $@; \
 	else \
 		touch $@; \
 	fi