[glib: 1/2] gbacktrace: Fix a set-but-not-used variable

[Philip Withnall <pwithnall src gnome org>]

commit 0694c1a5ade124d776e3d15b64206417f91ddf9b
Author: Philip Withnall <pwithnall endlessos org>
Date:   Thu Feb 17 21:46:39 2022 +0000

    gbacktrace: Fix a set-but-not-used variable
    
    It’s only used if building for lldb. Spotted in the log from an oss-fuzz
    build:
    https://oss-fuzz-build-logs.storage.googleapis.com/log-051f05da-adf5-42c1-8f14-5e36ba750573.txt:
    ```
    Step #12 - "compile-honggfuzz-address-x86_64": [36/1232] Compiling C object 
glib/libglib-2.0.a.p/gbacktrace.c.o
    Step #12 - "compile-honggfuzz-address-x86_64": ../../src/glib/glib/gbacktrace.c:324:24: warning: variable 
'line_idx' set but not used [-Wunused-but-set-variable]
    Step #12 - "compile-honggfuzz-address-x86_64":   int sel, idx, state, line_idx;
    Step #12 - "compile-honggfuzz-address-x86_64":                        ^
    Step #12 - "compile-honggfuzz-address-x86_64": 1 warning generated.
    ```
    
    Signed-off-by: Philip Withnall <pwithnall endlessos org>

 glib/gbacktrace.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)
---
diff --git a/glib/gbacktrace.c b/glib/gbacktrace.c
index eb9ec8d66..77cef100a 100644
--- a/glib/gbacktrace.c
+++ b/glib/gbacktrace.c
@@ -321,7 +321,10 @@ stack_trace (const char * const *args)
   fd_set fdset;
   fd_set readset;
   struct timeval tv;
-  int sel, idx, state, line_idx;
+  int sel, idx, state;
+#ifdef USE_LLDB
+  int line_idx;
+#endif
   char buffer[BUFSIZE];
   char c;
 
@@ -382,7 +385,9 @@ stack_trace (const char * const *args)
 #endif
 
   idx = 0;
+#ifdef USE_LLDB
   line_idx = 0;
+#endif
   state = 0;
 
   while (1)
@@ -399,7 +404,10 @@ stack_trace (const char * const *args)
         {
           if (read (out_fd[0], &c, 1))
             {
+#ifdef USE_LLDB
               line_idx += 1;
+#endif
+
               switch (state)
                 {
                 case 0:
@@ -423,7 +431,9 @@ stack_trace (const char * const *args)
                       _g_fprintf (stdout, "%s", buffer);
                       state = 0;
                       idx = 0;
+#ifdef USE_LLDB
                       line_idx = 0;
+#endif
                     }
                   break;
                 default: