tools: protect ccache detection to avoid pollution on stderr

Signed-off-by: Jean Privat <jean@pryen.org>

diff --git a/bin/gccx b/bin/gccx
index 8159f30..fa369a6 100755 (executable)
--- a/bin/gccx
+++ b/bin/gccx
@@ -69,7 +69,7 @@ return $res
 }
 
 cache=true
-if ccache -V 2>/dev/null >/dev/null; then
+if ( ccache -V ) 2>/dev/null >/dev/null; then
        cache=ccache
 fi