We have gcc atomic supports on all arch ports, no need to err out if
we're not on mainstream archs.

---
 build-config/common/m4/afs_gcc_atomic_builtins.m4 |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/build-config/common/m4/afs_gcc_atomic_builtins.m4
+++ b/build-config/common/m4/afs_gcc_atomic_builtins.m4
@@ -40,7 +40,7 @@ AC_LANG_POP([C])
 instruction_set=$(echo ${instruction_set} | cut -d: -f1)
 AC_MSG_RESULT([${instruction_set}])
 AS_IF([test "x${instruction_set}" = xunknown],
-    [AC_MSG_ERROR([cannot determine instruction set. Please report this to <AC_PACKAGE_BUGREPORT>.])])
+    [AC_MSG_WARN([cannot determine instruction set. Please report this to <AC_PACKAGE_BUGREPORT>.])])
 AC_SUBST([CPU_INSTRUCTION_SET], [${instruction_set}])
 # AC_DEFINE_UNQUOTED([$var], ...) does not work with AC_CONFIG_HEADERS, thus define all possible instruction sets
 AC_DEFINE_UNQUOTED([HAVE_CPU_INSTRUCTION_SET_PPC64], $(if test "x${instruction_set}" = xppc64; then echo 1; else echo 0; fi), [Instruction set ppc64])
