examples/general: fix warnings on not handled reference type in switch

examples/general.c:402:5: warning: enumeration value ‘GIT_REF_INVALID’ not handled in switch [-Wswitch]
examples/general.c:402:5: warning: enumeration value ‘GIT_REF_PACKED’ not handled in switch [-Wswitch]
examples/general.c:402:5: warning: enumeration value ‘GIT_REF_HAS_PEEL’ not handled in switch [-Wswitch]
examples/general.c:402:5: warning: enumeration value ‘GIT_REF_LISTALL’ not handled in switch [-Wswitch]

Signe-off-by: Kirill A. Shutemov <kirill@shutemov.name>

examples/general.c

@@ -408,6 +408,9 @@ int main (int argc, char** argv)
     case GIT_REF_SYMBOLIC:
       printf("%s => %s\n", refname, git_reference_target(ref));
       break;
+    default:
+      fprintf(stderr, "Unexpected reference type\n");
+      exit(1);
     }
   }