[PATCH 19/20] x86: purgatory: include header for warn() declaration

[Arnd Bergmann <arnd@xxxxxxxxxx>]

From: Arnd Bergmann <arnd@xxxxxxxx>

The purgatory code has uses parts of the decompressor and provides
its own warn() function, but has to include the corresponding
header file to avoid a -Wmissing-prototypes warning.

It turns out that this the function prototype actually differs
from the declaration, so change it to get a constant pointer
in the declaration and the other definition as well.

Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
 arch/x86/boot/compressed/error.c | 2 +-
 arch/x86/boot/compressed/error.h | 2 +-
 arch/x86/purgatory/purgatory.c   | 1 +
 3 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/x86/boot/compressed/error.c b/arch/x86/boot/compressed/error.c
index c881878e56d3..ce5ed7d8265e 100644
--- a/arch/x86/boot/compressed/error.c
+++ b/arch/x86/boot/compressed/error.c
@@ -7,7 +7,7 @@
 #include "misc.h"
 #include "error.h"
 
-void warn(char *m)
+void warn(const char *m)
 {
        error_putstr("\n\n");
        error_putstr(m);
diff --git a/arch/x86/boot/compressed/error.h b/arch/x86/boot/compressed/error.h
index 1de5821184f1..87062dea9a20 100644
--- a/arch/x86/boot/compressed/error.h
+++ b/arch/x86/boot/compressed/error.h
@@ -4,7 +4,7 @@
 
 #include <linux/compiler.h>
 
-void warn(char *m);
+void warn(const char *m);
 void error(char *m) __noreturn;
 
 #endif /* BOOT_COMPRESSED_ERROR_H */
diff --git a/arch/x86/purgatory/purgatory.c b/arch/x86/purgatory/purgatory.c
index 7558139920f8..aea47e793963 100644
--- a/arch/x86/purgatory/purgatory.c
+++ b/arch/x86/purgatory/purgatory.c
@@ -14,6 +14,7 @@
 #include <crypto/sha2.h>
 #include <asm/purgatory.h>
 
+#include "../boot/compressed/error.h"
 #include "../boot/string.h"
 
 u8 purgatory_sha256_digest[SHA256_DIGEST_SIZE] __section(".kexec-purgatory");
-- 
2.39.2