fix call to Cmd.capture in script/worker_analysis

Author: toy

script/worker_analysis

@@ -315,15 +315,15 @@ class Analyser
           images.map!{ |image| underlay_noise(image) }
         end
 
-        nrmse = Cmd.capture(*%W[
+        nrmse = Cmd.capture(%W[
           convert
           #{images[0]} -auto-orient
           #{images[1]} -auto-orient
           -metric RMSE
           -compare
           -format %[distortion]
           info:
-        ]).to_f
+        ].shelljoin).to_f
         unless $CHILD_STATUS.success?
           fail "failed comparison of #{@path} with #{other}"
         end