Don’t match stderr against FileCheck lines in test-sourcekit-lsp.py

Stderr contains log output from sourcekit-lsp but we want to match the LSP communication that happens over stdin/stdout. It seems that the additional stderr output can confuse `FileCheck`.

rdar://125139888

Author: ahoppen

test-sourcekit-lsp/test-sourcekit-lsp.py

@@ -2,8 +2,6 @@
 # language services.
 
 # REQUIRES: have-sourcekit-lsp
-# rdar://125139888
-# REQUIRES: platform=Darwin
 
 # Make a sandbox dir.
 # RUN: rm -rf %t.dir
@@ -14,7 +12,7 @@
 # RUN: %{FileCheck} --check-prefix CHECK-BUILD-LOG --input-file %t.build-log %s
 # CHECK-BUILD-LOG-NOT: error:
 
-# RUN: %{python} -u %s %{sourcekit-lsp} %t.dir/pkg 2>&1 | tee %t.run-log
+# RUN: %{python} -u %s %{sourcekit-lsp} %t.dir/pkg | tee %t.run-log
 # RUN: %{FileCheck} --input-file %t.run-log %s
 
 import argparse