[lldb/test] Update error message in debug-types-signature-loop.s

The error message changed in D144664.

Author: labath

lldb/test/Shell/SymbolFile/DWARF/x86/debug-types-signature-loop.s

@@ -4,7 +4,7 @@
 # RUN: ld.lld %t.o -o %t
 # RUN: %lldb %t -o "target variable e" -b | FileCheck %s
 
-# CHECK: e = <could not resolve type>
+# CHECK: Error: 'Unable to determine byte size.'
 
         .type   e,@object               # @e
         .section        .rodata,"a",@progbits