meson: Rename stdplus to stdplus_dep

This is the convention that meson builds should conform to.

Change-Id: Ia1a7e1a55e32200adbe37fa75ce02aee34df0219
Signed-off-by: William A. Kennington III <wak@google.com>
diff --git a/example/meson.build b/example/meson.build
index 8762e3b..d158045 100644
--- a/example/meson.build
+++ b/example/meson.build
@@ -4,5 +4,5 @@
 foreach example : examples
   executable(example, example + '.cpp',
              implicit_include_directories: false,
-             dependencies: stdplus)
+             dependencies: stdplus_dep)
 endforeach