Revert "[lldb] Speculative fix for trap_frame_sym_ctx.test"

This reverts commit 19d3f34.

Author: adrian-prantl

lldb/test/Shell/Unwind/trap_frame_sym_ctx.test

@@ -15,7 +15,7 @@ breakpoint set -n bar
 process launch
 # CHECK: stop reason = breakpoint 1.1
 
-thread backtrace -u
+thread backtrace
 # CHECK: frame #0: {{.*}}`bar
 # CHECK: frame #1: {{.*}}`tramp
 # CHECK: frame #2: {{.*}}`main