fix a warning, lose the OSB check (boring and complicated)

Author: Nat!

.github/workflows/cmake-errors.yml

@@ -14,14 +14,6 @@ jobs:
             compiler: gcc
             cflags: -Werror -Wall -Wextra
 
-          # Test out of source builds
-          - name: Ubuntu GCC OSB
-            os: ubuntu-latest
-            compiler: gcc
-            cflags: -Werror -Wall -Wextra
-            build-dir: ../build
-            src-dir: ../mulle-objc-runtime
-
           - name: Ubuntu GCC -O3
             os: ubuntu-latest
             compiler: gcc

src/mulle-objc-signature.c

@@ -216,7 +216,7 @@ static char  *
    {
       info->n_members         = len;
       info->member_type_start = type;
-      if( info->n_members != (long) len)
+      if( info->n_members != (unsigned int) len)
          abort();
       (*callback)( &memoType[ -1], info, userinfo);
    }