gdb/testsuite: remove duplicate test names from gdb.cp/gdb2384.exp

gdb/testsuite: remove duplicate test names from gdb.cp/gdb2384.exp

The test gdb.cp/gdb2384.exp contains some duplicate test names, and
also some test names with a string inside parentheses at the end.  In
order to resolve the duplicates the obvious choice would be to add yet
more strings inside parentheses at the end of names, however, this is
discouraged in our test naming scheme.

The string in parentheses originates from a comment in the test source
code, which naturally leads to including this comment in the test
name.

In this commit I have changed the comment in the test source to remove
the string in parentheses, I then rename the tests in the .exp script
to match, making sure that all test names are unique.

There should be no change in test coverage after this commit.

gdb/testsuite/ChangeLog:

	* gdb.cp/gdb2384.cc (main): Change comments used for breakpoints.
	* gdb.cp/gdb2384.exp: Change and extend test names to avoid
	duplicates, and also to avoid having a string inside parentheses
	at the end of test names.