Fix override argument for compile_dump to have two dashes

Change-Id: I60b905cc4620e6f1041417bf49214fcb8815d643

tools/compiledump.py

diff --git a/tools/compiledump.py b/tools/compiledump.py
index dbb4a18..98c9489 100755
--- a/tools/compiledump.py
+++ b/tools/compiledump.py
@@ -55,7 +55,7 @@
     '--r8-flags', '--r8_flags',
     help='Additional option(s) for the compiler.')
   parser.add_argument(
-    '-override',
+    '--override',
     help='Do not override any extracted dump in temp-dir',
     default=False,
     action='store_true')