style(expect): normalize debugging messages

A minor style cleanup to the messages printed by the Expect scripts to
make them a bit more consistent and descriptive.

Signed-off-by: Chris Kay <chris.kay@arm.com>
Change-Id: Ibd8ccb4423bd5aaeffc99c2f3602123794dc6200
diff --git a/expect/tftf_fault.exp b/expect/tftf_fault.exp
index 32aa41a..0288f03 100644
--- a/expect/tftf_fault.exp
+++ b/expect/tftf_fault.exp
@@ -10,7 +10,7 @@
 
 # Expect the test to have set a fault message
 if {![info exists ::env(tftf_fault_msg)]} {
-	puts "Fault message not set"
+	message "Fault message not set"
 	exit_uart -1
 }