avoid compiler warning



git-svn-id: svn://svn.valgrind.org/valgrind/trunk@4484 a5019735-40e9-0310-863c-91ae7b9d1cf9
diff --git a/coregrind/m_stacktrace.c b/coregrind/m_stacktrace.c
index ce3206a..bd17ee0 100644
--- a/coregrind/m_stacktrace.c
+++ b/coregrind/m_stacktrace.c
@@ -54,7 +54,9 @@
                             Addr ip, Addr sp, Addr fp, Addr lr,
                             Addr fp_min, Addr fp_max_orig )
 {
+#if defined(VGP_ppc32_linux)
    Bool  lr_is_first_RA = False; /* ppc only */
+#endif
    Bool  debug = False;
    Int   i;
    Addr  fp_max;