clang-tidy: Rename mako files

Rename the mako template files to end in .mako so that clang-tidy
doesn't run on them.

Tested:
elog-errors.hpp is still generated
callouts-gen.hpp is still generated

Change-Id: I9af4b9c31db9743b5af81d801f98901431bc7e2f
Signed-off-by: Matt Spinler <spinler@us.ibm.com>
diff --git a/tools/elog-gen.py b/tools/elog-gen.py
index 2b7fc49..b6991a9 100755
--- a/tools/elog-gen.py
+++ b/tools/elog-gen.py
@@ -288,7 +288,7 @@
         "-m",
         "--mako",
         dest="elog_mako",
-        default="elog-gen-template.mako.hpp",
+        default="elog-gen-template.hpp.mako",
         help="input mako template file to use",
     )