scripts/gdb: convert ModuleList to generator function

Analogously to the task list, convert the module list to a generator
function.  It noticeably simplifies the code.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ben Widawsky <ben@bwidawsk.net>
Cc: Borislav Petkov <bp@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/scripts/gdb/linux/symbols.py b/scripts/gdb/linux/symbols.py
index ae757fd..bf05e45 100644
--- a/scripts/gdb/linux/symbols.py
+++ b/scripts/gdb/linux/symbols.py
@@ -133,7 +133,7 @@
         gdb.execute("symbol-file vmlinux")
 
         self.loaded_modules = []
-        module_list = modules.ModuleList()
+        module_list = modules.module_list()
         if not module_list:
             gdb.write("no modules found\n")
         else: