Fix reference to sysroot in this test (broken in r226875).

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@226885 91177308-0d34-0410-b5e6-96231b3b80d8

test/Modules/self-import-header.m

 // rdar://13840148
 
 // RUN: rm -rf %t
-// RUN: %clang -fsyntax-only -isysroot %S/../Inputs/System/usr/include -fmodules -fmodules-cache-path=%t \
+// RUN: %clang -fsyntax-only -isysroot %S/Inputs/System/usr/include -fmodules -fmodules-cache-path=%t \
 // RUN:    -target x86_64-darwin \
 // RUN:    -F %S -I %S/Inputs/self-import-header %s -D__need_wint_t -Werror=implicit-function-declaration