[libglnx] macros: use size_t for glnx_strjoina len

[Colin Walters <walters src gnome org>]

commit 292cfc807e1662d5f6fe16f4d372e97973956955
Author: Jonathan Lebon <jlebon redhat com>
Date:   Mon Sep 25 15:38:25 2017 +0000

    macros: use size_t for glnx_strjoina len
    
    This was in my workspace for a while.
    `strlen` returns a `size_t` and `alloca` expects a `size_t`.

 glnx-macros.h |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/glnx-macros.h b/glnx-macros.h
index 1d4e175..6d8aca9 100644
--- a/glnx-macros.h
+++ b/glnx-macros.h
@@ -38,7 +38,7 @@ G_BEGIN_DECLS
         ({                                                              \
                 const char *_appendees_[] = { a, __VA_ARGS__ };         \
                 char *_d_, *_p_;                                        \
-                int _len_ = 0;                                          \
+                size_t _len_ = 0;                                       \
                 unsigned _i_;                                           \
                 for (_i_ = 0; _i_ < G_N_ELEMENTS(_appendees_) && _appendees_[_i_]; _i_++) \
                         _len_ += strlen(_appendees_[_i_]);              \