[test] Avoid loop-unroll.c test getting confused by fadd in git revision

Differential Revision: https://reviews.llvm.org/D73162

Author: rgal

clang/test/CodeGen/loop-unroll.c

@@ -37,6 +37,8 @@
 // CHECK-DISABLE-UNROLL-NOT: fmul
 // CHECK-DISABLE-UNROLL-NOT: fadd
 // CHECK-DISABLE-UNROLL-NOT: store
+// Limit scope of checking so this does not match "fadd" within git version string
+// CHECK-DISABLE-UNROLL: !0 =
 
 int printf(const char * restrict format, ...);