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
(cherry picked from commit 78ea2c38582da41eb8f9509a2130e702cdf0f1c9)
diff --git a/expect/spm-edk2-uart2.exp b/expect/spm-edk2-uart2.exp
index 74480bd..e91efb4 100644
--- a/expect/spm-edk2-uart2.exp
+++ b/expect/spm-edk2-uart2.exp
@@ -12,25 +12,25 @@
 
 expect {
 	"SPM Version" {
-		puts "<<Secure Partition booting>>"
+		message "Secure Partition booting"
 	}
 }
 
 expect {
 	"MmMain Done!" {
-		puts "<<Secure Partition booted>>"
+		message "Secure Partition booted"
 	}
 }
 
 expect {
 	"Received event - 0xC4000041 on cpu"  {
-		puts "<<Received event>>"
+		message "Received event"
 	}
 }
 
 expect {
 	"MmEntryPoint Done"  {
-		puts "<<Secure Partition done>>"
+		message "Secure Partition done"
 	}
 }