PM / Hibernate: Modify signature used to mark swap

Since we are adding compression to the kernel's hibernate code,
change signature used by it to mark swap spaces, so that earlier
kernels don't attempt to restore compressed images they cannot
handle.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>

kernel/power/swap.c

@@ -29,7 +29,7 @@
 
 #include "power.h"
 
-#define SWSUSP_SIG	"S1SUSPEND"
+#define HIBERNATE_SIG	"LINHIB0001"
 
 /*
  *	The swap map is a data structure used for keeping track of each page
@@ -195,7 +195,7 @@ static int mark_swapfiles(struct swap_map_handle *handle, unsigned int flags)
 	if (!memcmp("SWAP-SPACE",swsusp_header->sig, 10) ||
 	    !memcmp("SWAPSPACE2",swsusp_header->sig, 10)) {
 		memcpy(swsusp_header->orig_sig,swsusp_header->sig, 10);
-		memcpy(swsusp_header->sig,SWSUSP_SIG, 10);
+		memcpy(swsusp_header->sig, HIBERNATE_SIG, 10);
 		swsusp_header->image = handle->first_sector;
 		swsusp_header->flags = flags;
 		error = hib_bio_write_page(swsusp_resume_block,
@@ -916,7 +916,7 @@ int swsusp_check(void)
 		if (error)
 			goto put;
 
-		if (!memcmp(SWSUSP_SIG, swsusp_header->sig, 10)) {
+		if (!memcmp(HIBERNATE_SIG, swsusp_header->sig, 10)) {
 			memcpy(swsusp_header->sig, swsusp_header->orig_sig, 10);
 			/* Reset swap signature now */
 			error = hib_bio_write_page(swsusp_resume_block,