Test: print info on HSTRLEN test failure.

This additional info may provide more clues about the test randomly
failing from time to time. Probably the failure is due to some previous
test that overwrites the logical content in the Tcl variable, but this
will make the problem more obvious.

tests/unit/type/hash.tcl

@@ -406,7 +406,10 @@ start_server {tags {"hash"}} {
         foreach k [array names bighash *] {
             if {[string length $bighash($k)] ne [r hstrlen bighash $k]} {
                 set err "[string length $bighash($k)] != [r hstrlen bighash $k]"
-                break
+                puts "HSTRLEN and logical length mismatch:"
+                puts "key: $k"
+                puts "Logical content: $bighash($k)"
+                puts "Server  content: [r hget bighash $k]"
             }
         }
         set _ $err