smp: Use proper signed type to get return value of read(2).

diff --git a/src/libcharon/plugins/smp/smp.c b/src/libcharon/plugins/smp/smp.c
index 68935aa..830ed4c 100644 (file)
--- a/src/libcharon/plugins/smp/smp.c
+++ b/src/libcharon/plugins/smp/smp.c
@@ -627,7 +627,7 @@ static job_requeue_t process(int *fdp)
        int fd = *fdp;
        bool oldstate;
        char buffer[4096];
-       size_t len;
+       ssize_t len;
        xmlTextReaderPtr reader;
        char *id = NULL, *type = NULL;