M4 patches for bugs found in Gentoo sandbox builds.

Signed-off-by: Linus Walleij <triad@df.lth.se>
diff --git a/m4/byteorder.m4 b/m4/byteorder.m4
index 0ec97ea..e342be5 100644
--- a/m4/byteorder.m4
+++ b/m4/byteorder.m4
@@ -35,7 +35,7 @@
 ac_dir=`AS_DIRNAME(["$1"])`
 if test "$ac_dir" != "$1" && test "$ac_dir" != .; then
   # The file is in a subdirectory.
-  test ! -d "$ac_dir" && AS_MKDIR_P(["$ac_dir"])
+  test ! -d "$ac_dir" && (AS_MKDIR_P(["$ac_dir"]))
 fi
 
 # We're only interested in the target CPU, but it's not always set