Fix Makefile

I am unsure as to why, but the dependency expressed as "mcrouter: deps"
doesn't seem to work correctly.

When invoking the equivalent of "make mcrouter", I expect it to build
all the transitive dependencies of "deps", but it only builds the first
dependency that it determines it needs to build, and then exits with
a return value of "2".

I'm just reverting this to the previous style that is redundant but
works correctly.

mcrouter/scripts/Makefile_amazon-linux-2

@@ -53,7 +53,7 @@ all: mcrouter
 deps: .fbthrift-done .folly-done .fizz-done .wangle-done .fmt-done .zstd-done .glog-done .gflags-done .boost-done
 	touch $@
 
-mcrouter: deps
+mcrouter: .fbthrift-done .folly-done .fizz-done .wangle-done .fmt-done .zstd-done .glog-done .gflags-done .boost-done
 	${RECIPES_DIR}/mcrouter.sh $(PKG_DIR) $(INSTALL_DIR) $(INSTALL_AUX_DIR)
 	touch $@