mm/ksm: remove old GCC 4.9+ check

The minimum supported version of GCC has been raised to GCC 5.1.

Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/ksm.c b/mm/ksm.c
index 0253381..a5716fd 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -651,10 +651,8 @@
 	 * from &migrate_nodes. This will verify that future list.h changes
 	 * don't break STABLE_NODE_DUP_HEAD. Only recent gcc can handle it.
 	 */
-#if defined(GCC_VERSION) && GCC_VERSION >= 40903
 	BUILD_BUG_ON(STABLE_NODE_DUP_HEAD <= &migrate_nodes);
 	BUILD_BUG_ON(STABLE_NODE_DUP_HEAD >= &migrate_nodes + 1);
-#endif
 
 	if (stable_node->head == &migrate_nodes)
 		list_del(&stable_node->list);