Linux: Fix memory leak when inotify init failed

This introduces regex_compiled boolean to track whether the regex is
compiled successfully.

Closes #2229

src/linux_joystick.h

@@ -50,6 +50,7 @@ typedef struct _GLFWlibraryLinux
     int                     inotify;
     int                     watch;
     regex_t                 regex;
+    GLFWbool                regex_compiled;
     GLFWbool                dropped;
 } _GLFWlibraryLinux;