Remove absolute path form include test.

Review feedback/bot failure from r158459 by Simon Atanasyan and Benjamin Kramer (on IRC).

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@158464 91177308-0d34-0410-b5e6-96231b3b80d8

test/Frontend/rewrite-includes-missing.c

@@ -4,4 +4,4 @@
 // CHECK: {{^}}#if 0 /* expanded by -frewrite-includes */{{$}}
 // CHECK-NEXT: {{^}}#include "foobar.h"
 // CHECK-NEXT: {{^}}#endif /* expanded by -frewrite-includes */{{$}}
-// CHECK-NEXT: {{^}}# 4 "/usr/local/google/home/blaikie/Development/llvm/src/tools/clang/test/Frontend/rewrite-includes-missing.c" 2{{$}}
+// CHECK-NEXT: {{^}}# 4 "{{.*}}rewrite-includes-missing.c" 2{{$}}