scripts/: spelling fixes

Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
diff --git a/scripts/replay-dump.py b/scripts/replay-dump.py
index 3ba97a6..b89dc29 100755
--- a/scripts/replay-dump.py
+++ b/scripts/replay-dump.py
@@ -111,7 +111,7 @@
 # Decoders for each event type
 
 def decode_unimp(eid, name, _unused_dumpfile):
-    "Unimplimented decoder, will trigger exit"
+    "Unimplemented decoder, will trigger exit"
     print("%s not handled - will now stop" % (name))
     return False