staging: greybus: remove redundant assignment to variable is_empty

The variable is_empty is being initialized with a value that is never
read and it is being updated later with a new value. The
initialization is redundant and can be removed.

Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Vaibhav Agarwal <vaibhav.sr@gmail.com>
Reviewed-by: Mark Greer <mgreer@animalcreek.com>
Link: https://lore.kernel.org/r/20190704133031.28809-1-colin.king@canonical.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/greybus/audio_manager.c

@@ -86,7 +86,7 @@ EXPORT_SYMBOL_GPL(gb_audio_manager_remove);
 void gb_audio_manager_remove_all(void)
 {
 	struct gb_audio_manager_module *module, *next;
-	int is_empty = 1;
+	int is_empty;
 
 	down_write(&modules_rwsem);