Fix srfi-4 make-s8vector fill value type check

[Diego A. Mundo via Chicken-users]

make-s8vector is checking for an unsigned fill value, probably just a typo:

diff --git a/srfi-4.scm b/srfi-4.scm
index bfad8c84..2ae3733f 100644
--- a/srfi-4.scm
+++ b/srfi-4.scm
@@ -371,7 +371,7 @@ (define release-number-vector)
         (if (not init)
             v
             (begin
-              (check-uint-length init 8 'make-s8vector)
+              (check-int-length init 8 'make-s8vector)
               (do ((i 0 (##core#inline "C_fixnum_plus" i 1)))
                   ((##core#inline "C_fixnum_greater_or_equal_p" i len) v)
                 (##core#inline "C_u_i_s8vector_set" v i init) ) ) ) ) ) )



Diego