s390: convert to use __HEAD and HEAD_TEXT macros.

This has the consequence of changing the section name use for head
code from ".text.head" to ".head.text".  Since this commit changes all
users in the architecture, this change should be harmless.
Signed-off-by: Tim Abbott <tabbott@mit.edu>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/s390/kernel/head.S

@@ -23,6 +23,7 @@
  *
  */
 
+#include <linux/init.h>
 #include <asm/setup.h>
 #include <asm/lowcore.h>
 #include <asm/asm-offsets.h>
@@ -35,7 +36,7 @@
 #define ARCH_OFFSET	0
 #endif
 
-.section ".text.head","ax"
+__HEAD
 #ifndef CONFIG_IPL
 	.org   0
 	.long  0x00080000,0x80000000+startup	# Just a restart PSW

arch/s390/kernel/vmlinux.lds.S

@@ -29,8 +29,8 @@ SECTIONS
 	. = 0x00000000;
 	.text : {
 	_text = .;		/* Text and read-only data */
-		*(.text.head)
-	TEXT_TEXT
+		HEAD_TEXT
+		TEXT_TEXT
 		SCHED_TEXT
 		LOCK_TEXT
 		KPROBES_TEXT