xtensa: provide proper assembler function boundaries with ENDPROC()

Use ENDPROC() to mark the end of assembler functions.

Signed-off-by: Chris Zankel <chris@zankel.net>
diff --git a/arch/xtensa/kernel/head.S b/arch/xtensa/kernel/head.S
index bdc5078..417998c 100644
--- a/arch/xtensa/kernel/head.S
+++ b/arch/xtensa/kernel/head.S
@@ -47,16 +47,19 @@
 	 */
 
 	__HEAD
-	.globl _start
-_start:	_j	2f
+ENTRY(_start)
+
+	_j	2f
 	.align	4
 1:	.word	_startup
 2:	l32r	a0, 1b
 	jx	a0
 
+ENDPROC(_start)
+
 	.section .init.text, "ax"
-	.align 4
-_startup:
+
+ENTRY(_startup)
 
 	/* Disable interrupts and exceptions. */
 
@@ -230,6 +233,7 @@
 should_never_return:
 	j	should_never_return
 
+ENDPROC(_startup)
 
 /*
  * BSS section
@@ -239,6 +243,8 @@
 #ifdef CONFIG_MMU
 ENTRY(swapper_pg_dir)
 	.fill	PAGE_SIZE, 1, 0
+END(swapper_pg_dir)
 #endif
 ENTRY(empty_zero_page)
 	.fill	PAGE_SIZE, 1, 0
+END(empty_zero_page)