* lib/matrix.rb: [Doc] Fix Vector multiplication documentation [ci-skip]

[Fixes GH-837]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@49691 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

lib/matrix.rb

@@ -1907,7 +1907,7 @@ class Vector
   #++
 
   #
-  # Multiplies the vector by +x+, where +x+ is a number or another vector.
+  # Multiplies the vector by +x+, where +x+ is a number or a matrix.
   #
   def *(x)
     case x