Couple awt and swing tests have wrong require jtreg arguments

the following tests should use "os.family" instead of "os.name":
javax/swing/LookAndFeel/8145547/DemandGTK.java: @requires (os.name == "linux" | os.name == "solaris")
java/awt/TextArea/TextAreaCaretVisibilityTest/bug7129742.java: * @requires (os.family == "linux" | os.name == "solaris")
java/awt/WMSpecificTests/Mutter/MutterMaximizeTest.java: @requires (os.name == "linux" | os.name == "solaris")
java/awt/WMSpecificTests/Metacity/FullscreenDialogModality.java: * @requires (os.name == "linux" | os.name == "solaris")

see jtreg doc: http://openjdk.java.net/jtreg/tag-spec.html#requires_names