[clangd] Account for vendor in version string

The vendor will be prefixed to the "clangd" and can be an arbitrary
string, so account for it in the test.

Reviewed By: sammccall

Differential Revision: https://reviews.llvm.org/D90517

clang-tools-extra/clangd/test/log.test

@@ -1,5 +1,5 @@
 # RUN: env CLANGD_FLAGS=-index-file=no-such-index not clangd -lit-test </dev/null 2>&1 >/dev/null | FileCheck %s
-CHECK: I[{{.*}}] clangd version {{.*}}
+CHECK: I[{{.*}}]{{.*}} clangd version {{.*}}
 CHECK: Working directory: {{.*}}
 CHECK: argv[0]: clangd
 CHECK: argv[1]: -lit-test