Auto merge of #38374 - alexcrichton:makefile-fix, r=brson
Auto merge of #38374 - alexcrichton:makefile-fix, r=brson

mk: Fix `make check`

When the rustc-unicode crate was renamed to std-unicode we just need to continue
to filter it out of the crates being tested.

aidancully/rust,graydon/rust,aidancully/rust,GBGamer/rust,GBGamer/rust,GBGamer/rust,aidancully/rust,graydon/rust,graydon/rust,GBGamer/rust,GBGamer/rust,aidancully/rust,aidancully/rust,GBGamer/rust,GBGamer/rust,aidancully/rust,GBGamer/rust,graydon/rust,graydon/rust,graydon/rust