uprobes: shift put_uprobe() from delete_uprobe() to uprobe_unregister()

Kill the extra get_uprobe() + put_uprobe() in uprobe_unregister() and
move the possibly final put_uprobe() from delete_uprobe() to its only
caller, uprobe_unregister().

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Link: https://lore.kernel.org/r/20240801132749.GA8817@redhat.com