[compiler-rt][test] Rewrote test to remove curly braces (#105696)

This patch removes curly braces from a test, as lit's internal shell
implementation does not support curly brace syntax.

Fixes #102382.

Author: connieyzhu

compiler-rt/test/asan/TestCases/Linux/dlopen-mixed-c-cxx.c

@@ -1,7 +1,7 @@
 // RUN: %clangxx_asan -xc++ -shared -fPIC -o %t.so - < %s
 // RUN: %clang_asan %s -o %t.out -ldl
 //
-// RUN: { env ASAN_OPTIONS=verbosity=1 %t.out %t.so || : ; } 2>&1 | FileCheck %s
+// RUN: env ASAN_OPTIONS=verbosity=1 not %t.out %t.so 2>&1 | FileCheck %s
 //
 // CHECK: AddressSanitizer: failed to intercept '__cxa_throw'
 //