arm: Force non-executable stack (part 2)

This was supposed to be part of commit 63a10bbc but I pushed
from the wrong machine. This fixes cross compiling to arm.

Signed-off-by: Erik de Castro Lopo <erikd@mega-nerd.com>
(cherry picked from commit 1a4374c1)

aclocal.m4

@@ -571,7 +571,7 @@ AC_DEFUN([FPTOOLS_SET_C_LD_FLAGS],
         # gcc to link using the gold linker.
         # Forcing LD to be ld.gold is done in FIND_LD m4 macro.
         $3="$$3 -fuse-ld=gold -Wl,-z,noexecstack"
-        $4="$$4 -z,noexecstack"
+        $4="$$4 -z noexecstack"
         ;;
     esac