Update the expected match string.
o lldbtest.py:
Indicate when a command fails, even if there is nothing in the error stream.
o TestHelp.py:
Add a regression test case for 'help image dump symtab'.
o CommandObjectHelp.cpp:
Some of the logic branches with successful help command results were not tagged
with a Success Status. They are fixed now. This is important for Python
interaction.
llvm-svn: 116062