moveconfig: Use re.fullmatch() to avoid extra check

Simplify the code by using the available function.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Alper Nebi Yasak <alpernebiyasak@gmail.com>
diff --git a/tools/moveconfig.py b/tools/moveconfig.py
index ecc6e16..84bc875 100755
--- a/tools/moveconfig.py
+++ b/tools/moveconfig.py
@@ -1607,8 +1607,7 @@
         bool: True if any CONFIG matches the regex
     """
     for cfg in configs:
-        m_cfg = re_match.match(cfg)
-        if m_cfg and m_cfg.span()[1] == len(cfg):
+        if re_match.fullmatch(cfg):
             return True
     return False