x86: introduce fill_ldt

This patch introduces fill_ldt(), which populates a ldt descriptor
from a user_desc in once, instead of relying in the LDT_entry_a and
LDT_entry_b macros

Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/arch/x86/kernel/ldt.c b/arch/x86/kernel/ldt.c
index 7eb0c8a..3e872b4 100644
--- a/arch/x86/kernel/ldt.c
+++ b/arch/x86/kernel/ldt.c
@@ -223,8 +223,7 @@
 		}
 	}
 
-	ldt.a = LDT_entry_a(&ldt_info);
-	ldt.b = LDT_entry_b(&ldt_info);
+	fill_ldt(&ldt, &ldt_info);
 	if (oldmode)
 		ldt.avl = 0;