[hackers] [sbase] Fix warning in join(1) || sin

[git]

commit e52845281a16029d264b36c7c9a746a6cd70f268
Author:     sin <s...@2f30.org>
AuthorDate: Tue Dec 15 09:39:57 2015 +0000
Commit:     sin <s...@2f30.org>
CommitDate: Tue Dec 15 09:40:52 2015 +0000

    Fix warning in join(1)
    
    Spotted by Random832.

diff --git a/join.c b/join.c
index 1a08927..4c68ad3 100644
--- a/join.c
+++ b/join.c
@@ -263,7 +263,7 @@ addtospan(struct span *sp, FILE *fp, int reset)
        char *newl = NULL;
        size_t len, size = 0;
 
-       if ((len = getline(&newl, &size, fp)) == -1) {
+       if ((len = getline(&newl, &size, fp)) == (size_t)-1) {
                if (ferror(fp))
                        eprintf("getline:");
                else