fontconfig/pattern.scm (pattern-get): Take symbol instead of string.

* examples/example.scm: Update accordingly.

examples/example.scm

@@ -10,9 +10,9 @@ Font located at: ~A
 Style & Family: ~A ~A
 Fc Match String: ~A
 "
-             (pattern-get pat "file")
-             (pattern-get pat "style")
-             (pattern-get pat "family")
+             (pattern-get pat 'file)
+             (pattern-get pat 'style)
+             (pattern-get pat 'family)
              (pattern->format pat "%{=fcmatch}")))
    (pattern-list pattern)))
 

fontconfig/pattern.scm

@@ -160,7 +160,9 @@
 (define (pattern-get pattern attr)
   (let ((out (bytevector->pointer (make-bytevector (* int 2)))))
     (ffi:fontconfig-pattern-get
-     (unwrap-pattern pattern) (string->pointer attr) 0 out)
+     (unwrap-pattern pattern)
+     (string->pointer (symbol->string attr))
+     0 out)
     (fontconfig-value out)))
 
 (define (pointer->font-list ptr)